diff --git a/docs/en_US/Compressor/CompressionReference.md b/docs/en_US/Compressor/CompressionReference.md
index c190a46eb6..8b2444aa91 100644
--- a/docs/en_US/Compressor/CompressionReference.md
+++ b/docs/en_US/Compressor/CompressionReference.md
@@ -18,6 +18,16 @@
 ..  autoclass:: nni.compression.torch.utils.shape_dependency.ChannelDependency
     :members:
 
-..  autoclass:: nni.compression.torch.utils.mask_conflict.MaskConflict
+..  autoclass:: nni.compression.torch.utils.shape_dependency.GroupDependency
     :members:
+
+..  autoclass:: nni.compression.torch.utils.mask_conflict.CatMaskPadding
+    :members:
+
+..  autoclass:: nni.compression.torch.utils.mask_conflict.GroupMaskConflict
+    :members:
+
+..  autoclass:: nni.compression.torch.utils.mask_conflict.ChannelMaskConflict
+    :members:
+
 ```
diff --git a/docs/en_US/Compressor/CompressionUtils.md b/docs/en_US/Compressor/CompressionUtils.md
index 09418912b9..066225c730 100644
--- a/docs/en_US/Compressor/CompressionUtils.md
+++ b/docs/en_US/Compressor/CompressionUtils.md
@@ -116,8 +116,6 @@ Set 12,layer4.1.conv1
 When the masks of different layers in a model have conflict (for example, assigning different sparsities for the layers that have channel dependency), we can fix the mask conflict by MaskConflict. Specifically, the MaskConflict loads the masks exported by the pruners(L1FilterPruner, etc), and check if there is mask conflict, if so, MaskConflict sets the conflicting masks to the same value.
 
 ```
-from nni.compression.torch.utils.mask_conflict import MaskConflict
-mc = MaskConflict('./resnet18_mask', net, data)
-mc.fix_mask_conflict()
-mc.export('./resnet18_fixed_mask')
+from nni.compression.torch.utils.mask_conflict import fix_mask_conflict
+fixed_mask = fix_mask_conflict('./resnet18_mask', net, data)
 ```
\ No newline at end of file
diff --git a/src/sdk/pynni/nni/_graph_utils.py b/src/sdk/pynni/nni/_graph_utils.py
index 445aaebd58..5fec566b46 100644
--- a/src/sdk/pynni/nni/_graph_utils.py
+++ b/src/sdk/pynni/nni/_graph_utils.py
@@ -10,6 +10,7 @@
 from torch.utils.tensorboard._pytorch_graph import NodePy, NodePyIO, NodePyOP, GraphPy
 CLASSTYPE_KIND = 'ClassType'
 GETATTR_KIND = 'prim::GetAttr'
+CAT_KIND = 'aten::cat'
 
 _logger = logging.getLogger(__name__)
 
@@ -236,6 +237,7 @@ def __init__(self, model=None, dummy_input=None, traced_model=None):
         super().__init__(model, dummy_input, traced_model)
         self.global_count = 0
         self.name_to_node, self.input_to_node, self.output_to_node = self._build_graph()
+        self._extract_auxiliary_info()
 
     def _expand_non_prim_node(self, node, nodes, input_to_node, output_to_node,
                               module_type):
@@ -364,6 +366,58 @@ def _expand_module_node(self, node, node_name, unique_name, op_type, nodes,
                              node_group, inputs=inputs, outputs=outputs)
         return nodepy
 
+    def _extract_cat_info(self, node_group, cpp_node):
+        """
+        Extract the detail information of the cat operation,
+        such the order of the input tensor, the shape of each
+        input tensor, the output shape, and the cat dimension.
+
+        Parameters
+        ----------
+        node_group : NodePyGroup
+        cpp_node: torch._C.Node
+            It should be ```aten::cat``` node
+
+        Returns
+        -------
+        dict
+            Include auxiliary information for the cat operation.
+            This dict objec has four keys: 'cat_dim', 'out_shape',
+            'in_order' and 'in_shape'. cat_dim is the dimension of
+            the cat operation to concat the input tensors. out_shape
+            is the shape of the output tensor of the cat operation.
+            in_order is an ordered list which contains the corresponding
+            parent operaion nodes of the input tensors. in_shape is also
+            an ordered list that contains the input shapes of the input
+            tensor.
+        """
+        # only suport the cat operation
+        assert cpp_node.kind() == CAT_KIND
+        cat_info = {}
+        # get the shape of the output tensor
+        t_output = cpp_node.output()
+        out_shape = t_output.type().sizes()
+        cat_info['out_shape'] = out_shape
+        # get the cat dimension
+        inputs = cpp_node.inputs()
+        cat_dim = list(inputs)[1].toIValue()
+        cat_info['cat_dim'] = cat_dim
+        # get the order of the input tensors
+        # To get the order of the input tensors, we need
+        # to be aware of the topology of the model, which
+        # means we should extract the auxiliary information
+        # after the build_index function.
+        input_order = []
+        list_construct_cpp = list(cpp_node.inputs())[0].node()
+        input_tensors = list(list_construct_cpp.inputs())
+        for _tensor in input_tensors:
+            debug_name = _tensor.debugName()
+            input_order.append(self.output_to_node[debug_name].unique_name)
+        cat_info['in_order'] = input_order
+        input_shapes = [t.type().sizes() for t in input_tensors]
+        cat_info['in_shape'] = input_shapes
+        return cat_info
+
     def _extract_shape_info(self, node):
         """
         Extract the shape information of ```aten::view``` node
@@ -541,8 +595,8 @@ def _build_graph(self):
                     node, nodes, input_to_node, output_to_node, 'func')
                 nodes_py.nodes_op.append(node_group)
                 # get shape infor for view (aten::view) func
-                if node_group.op_type in ['aten::view', 'aten::flatten']:
-                    node_group.auxiliary = self._extract_shape_info(node)
+                # if node_group.op_type in ['aten::view', 'aten::flatten']:
+                #     node_group.auxiliary = self._extract_shape_info(node)
 
         for node in graph.outputs():  # Create sink nodes for output ops
             node_py = NodePyIO(node, 'output')
@@ -552,6 +606,26 @@ def _build_graph(self):
         # build index
         return self._build_index(self.nodes_py.nodes_op)
 
+    def _extract_auxiliary_info(self):
+        """
+        Extract the auxiliary information for the nodegroups
+        if necessary. For example, view/flatten operations may
+        need the shape of the input tensor and output tensor.
+        """
+        # extract the input & output shape for the view and flatten
+        for node_group in self.nodes_py.nodes_op:
+            if node_group.op_type in ['aten::view', 'aten::flatten', 'aten::mean', 'aten::reshape']:
+                # get shape infor for view (aten::view) func
+                cpp_node = list(filter(lambda x: x.kind() == node_group.op_type,
+                                       node_group.node_cpps))[0]
+                node_group.auxiliary = self._extract_shape_info(cpp_node)
+            elif node_group.op_type == CAT_KIND:
+                # get the detail information for cat func
+                cpp_node = list(filter(lambda x: x.kind() == node_group.op_type,
+                                       node_group.node_cpps))[0]
+                node_group.auxiliary = self._extract_cat_info(
+                    node_group, cpp_node)
+
     def find_predecessors(self, unique_name):
         """
         Find predecessor node of the given node
diff --git a/src/sdk/pynni/nni/compression/torch/speedup/compress_modules.py b/src/sdk/pynni/nni/compression/torch/speedup/compress_modules.py
index 666c497482..0b349f9d5c 100644
--- a/src/sdk/pynni/nni/compression/torch/speedup/compress_modules.py
+++ b/src/sdk/pynni/nni/compression/torch/speedup/compress_modules.py
@@ -14,7 +14,11 @@
     'AvgPool2d': lambda module, mask: no_replace(module, mask),
     'AdaptiveAvgPool2d': lambda module, mask: no_replace(module, mask),
     'ReLU': lambda module, mask: no_replace(module, mask),
-    'Linear': lambda module, mask: replace_linear(module, mask)
+    'ReLU6': lambda module, mask: no_replace(module, mask),
+    'Linear': lambda module, mask: replace_linear(module, mask),
+    'Dropout': lambda module, mask: no_replace(module, mask),
+    'Dropout2d': lambda module, mask: no_replace(module, mask),
+    'Dropout3d': lambda module, mask: no_replace(module, mask)
 }
 
 def no_replace(module, mask):
@@ -111,6 +115,7 @@ def replace_conv2d(conv, mask):
     else:
         out_channels_index = mask.output_mask.mask_index[1]
         out_channels = out_channels_index.size()[0]
+
     _logger.debug("replace conv2d with in_channels: %d, out_channels: %d", in_channels, out_channels)
     new_conv = torch.nn.Conv2d(in_channels=in_channels,
                                out_channels=out_channels,
@@ -118,21 +123,45 @@ def replace_conv2d(conv, mask):
                                stride=conv.stride,
                                padding=conv.padding,
                                dilation=conv.dilation,
-                               groups=1, # currently only support groups is 1
+                               groups=conv.groups,
                                bias=conv.bias is not None,
                                padding_mode=conv.padding_mode)
+
     new_conv.to(conv.weight.device)
     tmp_weight_data = tmp_bias_data = None
+
     if mask.output_mask is not None:
         tmp_weight_data = torch.index_select(conv.weight.data, 0, out_channels_index)
         if conv.bias is not None:
             tmp_bias_data = torch.index_select(conv.bias.data, 0, out_channels_index)
-    # NOTE: does not support group
+    else:
+        tmp_weight_data = conv.weight.data
+    # For the convolutional layers that have more than one group
+    # we need to copy the weight group by group, because the input
+    # channal is also divided into serveral groups and each group
+    # filter may have different input channel indexes.
+    input_step = int(conv.in_channels / conv.groups)
+    in_channels_group = int(in_channels / conv.groups)
+    filter_step = int(out_channels / conv.groups)
     if mask.input_mask is not None:
-        tmp_weight_data = torch.index_select(conv.weight.data if tmp_weight_data is None else tmp_weight_data,
-                                             1, in_channels_index)
-    assert tmp_weight_data is not None, "Conv2d weight should be updated based on masks"
-    new_conv.weight.data.copy_(tmp_weight_data)
+        for groupid in range(conv.groups):
+            start = groupid * input_step
+            end = (groupid + 1) * input_step
+            current_input_index = list(filter(lambda x: start <= x and x < end, in_channels_index.tolist()))
+            # shift the global index into the group index
+            current_input_index = [x-start for x in current_input_index]
+            # if the groups is larger than 1, the input channels of each
+            # group should be pruned evenly.
+            assert len(current_input_index) == in_channels_group, \
+                'Input channels of each group are not pruned evenly'
+            current_input_index = torch.tensor(current_input_index).to(tmp_weight_data.device) # pylint: disable=not-callable
+            f_start = groupid * filter_step
+            f_end = (groupid + 1) * filter_step
+            new_conv.weight.data[f_start:f_end] = torch.index_select(tmp_weight_data[f_start:f_end], 1, current_input_index)
+    else:
+        new_conv.weight.data.copy_(tmp_weight_data)
+
     if conv.bias is not None:
         new_conv.bias.data.copy_(conv.bias.data if tmp_bias_data is None else tmp_bias_data)
+
     return new_conv
diff --git a/src/sdk/pynni/nni/compression/torch/speedup/compressor.py b/src/sdk/pynni/nni/compression/torch/speedup/compressor.py
index 084d5b8ea4..4b569d7e4f 100644
--- a/src/sdk/pynni/nni/compression/torch/speedup/compressor.py
+++ b/src/sdk/pynni/nni/compression/torch/speedup/compressor.py
@@ -4,6 +4,7 @@
 import logging
 import torch
 from nni._graph_utils import build_module_graph
+from nni.compression.torch.utils.mask_conflict import fix_mask_conflict
 from .compress_modules import replace_module
 from .infer_shape import ModuleMasks, infer_from_mask, infer_from_inshape, infer_from_outshape
 
@@ -53,9 +54,10 @@ def __init__(self, model, dummy_input, masks_file, map_location=None):
         self.bound_model = model
         self.masks = torch.load(masks_file, map_location)
         self.inferred_masks = dict() # key: module_name, value: ModuleMasks
+        self.dummy_input = dummy_input
         self.torch_graph = build_module_graph(model, dummy_input)
 
-    def infer_module_mask(self, module_name, mask=None, in_shape=None, out_shape=None):
+    def infer_module_mask(self, module_name, last_module, mask=None, in_shape=None, out_shape=None):
         """
         Infer input shape / output shape based on the module's weight mask / input shape / output shape.
 
@@ -71,6 +73,8 @@ def infer_module_mask(self, module_name, mask=None, in_shape=None, out_shape=Non
         ----------
         module_name : str
             The name of the node
+        last_module : str
+            The name of last visited node
         mask : tensor of mask or ModuleMasks
             Mask of the weights in this node (i.e., module)
         in_shape : ModuleMasks
@@ -100,10 +104,17 @@ def infer_module_mask(self, module_name, mask=None, in_shape=None, out_shape=Non
                 raise RuntimeError(
                     "Has not supported infering output shape from input shape for module/function: `{}`, {}"
                     .format(m_type, module_name))
-            if m_type in ['aten::view', 'aten::flatten']:
+            if m_type in ['aten::view', 'aten::flatten', 'aten::mean', 'aten::reshape']:
                 output_cmask = infer_from_inshape[m_type](module_masks,
                                                           in_shape,
                                                           self.torch_graph.name_to_node[module_name].auxiliary)
+            elif m_type in ['aten::cat']:
+                # To calculate the mask for concat operation, the output shape
+                # , cat dimension, and the order of the input parameters.
+                output_cmask = infer_from_inshape[m_type](module_masks,
+                                                          in_shape,
+                                                          self.torch_graph.name_to_node[module_name].auxiliary,
+                                                          last_module)
             else:
                 output_cmask = infer_from_inshape[m_type](module_masks, in_shape)
         if out_shape is not None:
@@ -117,18 +128,19 @@ def infer_module_mask(self, module_name, mask=None, in_shape=None, out_shape=Non
         if input_cmask:
             predecessors = self.torch_graph.find_predecessors(module_name)
             for _module_name in predecessors:
-                self.infer_module_mask(_module_name, out_shape=input_cmask)
+                self.infer_module_mask(_module_name, module_name, out_shape=input_cmask)
         if output_cmask:
             successors = self.torch_graph.find_successors(module_name)
             for _module_name in successors:
-                self.infer_module_mask(_module_name, in_shape=output_cmask)
+                self.infer_module_mask(_module_name, module_name, in_shape=output_cmask)
 
     def infer_modules_masks(self):
         """
         Do shape inference of involved modules, including the shape of weights, inputs, output
         """
         for module_name, mask in self.masks.items():
-            self.infer_module_mask(module_name, mask=mask)
+            _logger.debug('Start mask inference from %s', module_name)
+            self.infer_module_mask(module_name, None, mask=mask)
 
     def replace_compressed_modules(self):
         """
@@ -144,19 +156,20 @@ def replace_compressed_modules(self):
             _logger.debug("replace %s, in %s type, with op_type %s",
                           module_name, g_node.type, g_node.op_type)
             if g_node.type == 'module':
-                super_module, leaf_module = get_module_by_name(self.bound_model, module_name)
+                super_module, leaf_module = get_module_by_name(self.bound_model, g_node.name)
                 m_type = g_node.op_type
                 if not m_type in replace_module:
                     raise RuntimeError("Has not supported replacing the module: `{}`".format(m_type))
-                _logger.info("replace module (name: %s, op_type: %s)", module_name, m_type)
+                _logger.info("replace module (name: %s, op_type: %s)", g_node.name, m_type)
                 compressed_module = replace_module[m_type](leaf_module, self.inferred_masks[module_name])
-                setattr(super_module, module_name.split('.')[-1], compressed_module)
+                setattr(super_module, g_node.name.split('.')[-1], compressed_module)
             elif g_node.type == 'func':
                 _logger.info("Warning: cannot replace (name: %s, op_type: %s) which is func type",
                              module_name, g_node.op_type)
             else:
                 raise RuntimeError("Unsupported node type: {}".format(g_node.type))
 
+
     def speedup_model(self):
         """
         There are basically two steps:
@@ -165,6 +178,8 @@ def speedup_model(self):
         """
         training = self.bound_model.training
         _logger.info("start to speed up the model")
+        _logger.info("fix the mask conflict of the interdependent layers")
+        fix_mask_conflict(self.masks, self.bound_model, self.dummy_input)
         _logger.info("infer module masks...")
         self.infer_modules_masks()
         _logger.info("replace compressed modules...")
diff --git a/src/sdk/pynni/nni/compression/torch/speedup/infer_shape.py b/src/sdk/pynni/nni/compression/torch/speedup/infer_shape.py
index 82401659ec..964c5046ec 100644
--- a/src/sdk/pynni/nni/compression/torch/speedup/infer_shape.py
+++ b/src/sdk/pynni/nni/compression/torch/speedup/infer_shape.py
@@ -8,11 +8,13 @@
 
 import torch
 
+
 class CoarseMask:
     """
     Coarse grained mask for a given tensor, here tensor could be weights,
     input tensor, or output tensor
     """
+
     def __init__(self, num_dim):
         """
         Parameters
@@ -50,13 +52,26 @@ def merge_index(index_a, index_b):
         -------
         tensor
             The merged index (1-dimension) tensor
+            Note that: the output tensor will be moved
+            to the same device as index_a.
         """
+        device = index_a.device
         s = set()
-        for num in index_a:
+        for num in index_a.tolist():
+            # we need to transfer the tensor to list here
+            # first, directly traversing the tensor by for
+            # loop will return the list of tensor(x) object,
+            # even the value are the same, but they are different
+            # tensor objects, so the set will contains multiple
+            # tensor objects that has the same value. For example
+            # for num in torch.ones(2):
+            #   s.add(num)
+            # s will be {tensor(1), tensor(1)}
             s.add(num)
-        for num in index_b:
+        for num in index_b.tolist():
             s.add(num)
-        return torch.tensor(sorted(s)) # pylint: disable=not-callable
+        # move the output tensor to the same device with index_a
+        return torch.tensor(sorted(s)).to(device)  # pylint: disable=not-callable
 
     def merge(self, cmask):
         """
@@ -86,10 +101,65 @@ def merge(self, cmask):
     def __repr__(self):
         return 'mask_index: {}'.format(self.mask_index)
 
+    def eq_on_dim(self, other, dim):
+        assert isinstance(other, CoarseMask)
+        if self.mask_index[dim] is None and other.mask_index[dim] is None:
+            return True
+        elif isinstance(self.mask_index[dim], torch.Tensor) \
+                and isinstance(other.mask_index[dim], torch.Tensor):
+            return torch.equal(self.mask_index[dim], other.mask_index[dim])
+        else:
+            return False
+
+    def __eq__(self, other):
+        assert isinstance(other, CoarseMask)
+        if len(self.mask_index) != len(other.mask_index):
+            return False
+        for i in range(len(self.mask_index)):
+            if not self.eq_on_dim(other, i):
+                return False
+        return True
+
+    def __lt__(self, other):
+        """
+        Judge if the mask is a subset of another CoarseMask.
+        """
+        assert isinstance(other, CoarseMask)
+        for dim, _ in enumerate(self.mask_index):
+            # if self has more dimensions
+            if dim >= len(other.mask_index):
+                return False
+            if self.mask_index[dim] is None:
+                # if no mask on this dimension, then we have less
+                # masks then the other CoraseMask.
+                continue
+            elif other.mask_index[dim] is None:
+                return False
+            else:
+                s1 = set(self.mask_index[dim].tolist())
+                s2 = set(other.mask_index[dim].tolist())
+                if not s1 < s2:
+                    return False
+        return True
+
+    def __le__(self, other):
+        """
+        Return if self's mask is less or equal to other's mask.
+        """
+        assert isinstance(other, CoarseMask)
+        if self.__lt__(other) or self.__eq__(other):
+            return True
+        return False
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+
 class ModuleMasks:
     """
     The masks of a module, including the masks for weights, inputs, output
     """
+
     def __init__(self, module_name):
         """
         Parameters
@@ -136,6 +206,7 @@ def __repr__(self):
             self.input_mask, self.output_mask, self.param_masks
         )
 
+
 """
 Infer input and output shape of a module/function from its weight mask
 """
@@ -149,18 +220,27 @@ def __repr__(self):
 """
 infer_from_inshape = {
     'ReLU': lambda module_masks, mask: relu_inshape(module_masks, mask),
+    'ReLU6': lambda module_masks, mask: relu_inshape(module_masks, mask),
     'aten::relu': lambda module_masks, mask: relu_inshape(module_masks, mask),
     'Conv2d': lambda module_masks, mask: conv2d_inshape(module_masks, mask),
     'MaxPool2d': lambda module_masks, mask: maxpool2d_inshape(module_masks, mask),
     'aten::max_pool2d': lambda module_masks, mask: maxpool2d_inshape(module_masks, mask),
     'aten::avg_pool2d': lambda module_masks, mask: maxpool2d_inshape(module_masks, mask),
+    'aten::adaptive_avg_pool2d': lambda module_masks, mask: maxpool2d_inshape(module_masks, mask),
     'AvgPool2d': lambda module_masks, mask: maxpool2d_inshape(module_masks, mask),
     'AdaptiveAvgPool2d': lambda module_masks, mask: maxpool2d_inshape(module_masks, mask),
     'aten::size': lambda module_masks, mask: size_inshape(module_masks, mask),
     'aten::view': lambda module_masks, mask, shape: view_inshape(module_masks, mask, shape),
-    'aten::flatten': lambda module_masks, mask, shape: view_inshape(module_masks, mask, shape), # support only start_dim=1
+    'aten::reshape': lambda module_masks, mask, shape: view_inshape(module_masks, mask, shape),
+    # support only start_dim=1
+    'aten::flatten': lambda module_masks, mask, shape: view_inshape(module_masks, mask, shape),
     'Linear': lambda module_masks, mask: linear_inshape(module_masks, mask),
-    'BatchNorm2d': lambda module_masks, mask: batchnorm2d_inshape(module_masks, mask)
+    'BatchNorm2d': lambda module_masks, mask: batchnorm2d_inshape(module_masks, mask),
+    'aten::add_': lambda module_masks, mask: add_inshape(module_masks, mask),
+    'aten::add': lambda module_mask, mask: add_inshape(module_mask, mask),
+    'aten::cat': lambda module_mask, mask, cat_info, last_visited: cat_inshape(module_mask, mask, cat_info, last_visited),
+    'aten::mean': lambda module_masks, mask, shape: mean_inshape(module_masks, mask, shape),
+    'Dropout': lambda module_masks, mask: dropout_inshape(module_masks, mask)
 }
 
 """
@@ -170,6 +250,120 @@ def __repr__(self):
     'Conv2d': lambda module_masks, mask: conv2d_outshape(module_masks, mask)
 }
 
+def dropout_inshape(module_masks, mask):
+    if module_masks.input_mask is None:
+        module_masks.set_input_mask(mask)
+        module_masks.set_output_mask(mask)
+        return module_masks.output_mask
+    # if alreay visited
+    assert module_masks.input_mask <= mask
+    if module_masks.input_mask == mask:
+        return None
+    module_masks.set_input_mask(mask)
+    module_masks.set_output_mask(mask)
+    return module_masks.output_mask
+
+
+
+def cat_inshape(module_masks, mask, cat_info, last_visited):
+    """
+    Inference the output mask of the cat operation from the
+    input mask.
+
+    Parameters
+    ----------
+    module_masks : ModuleMasks
+        The ModuleMasks instance of the batchnorm2d
+    mask : CoarseMask
+        The mask of its input tensor
+    cat_info: dict
+        Dict object that records the necessary information
+        of cat operation, such as the order of the input
+        tensors.
+    last_visited: str
+        The unique_name of the last visited node group.
+
+    Returns
+    -------
+    CoarseMask
+        The mask of its output tensor
+
+    """
+    assert isinstance(mask, CoarseMask)
+    out_shape = cat_info['out_shape']
+    cat_dim = cat_info['cat_dim']
+    in_order = cat_info['in_order']
+    in_shape = cat_info['in_shape']
+    if module_masks.output_mask is None:
+        # First visit to this cat node
+        # initialize the mask based on
+        # the number of the output channel.
+        output_mask = CoarseMask(num_dim=len(out_shape))
+        for dim, _ in enumerate(out_shape):
+            if dim == cat_dim:
+                if mask.mask_index[dim] is None:
+                    continue
+                device = mask.mask_index[dim].device
+                # calculate the offset of the mask
+                pos = in_order.index(last_visited)
+                offsets = [in_shape[i][cat_dim]
+                           for i, _ in enumerate(in_shape)]
+                offset = 0
+                for i in range(pos):
+                    offset += offsets[i]
+                _tmp_mask = (mask.mask_index[dim] + offset).to(device)
+                output_mask.mask_index[dim] = _tmp_mask
+            else:
+                # directly copy the mask
+                if mask.mask_index[dim] is not None:
+                    output_mask.mask_index[dim] = mask.mask_index[dim].data.clone(
+                    )
+        module_masks.set_output_mask(output_mask)
+
+        return module_masks.output_mask
+    # If this cat node is already visited, we need
+    # validating if the mask is legel, for cat operation,
+    # the mask on the 'cat_dim' dimension should be stitched
+    # together. In the other dimensions, the mask should be
+    # the same, else the mask is not legal.
+    for dim, _ in enumerate(out_shape):
+        if dim == cat_dim:
+            if mask.mask_index[dim] is None:
+                continue
+            pos = in_order.index(last_visited)
+            offsets = [in_shape[i][cat_dim] for i, _ in enumerate(in_shape)]
+            offset = 0
+            for i in range(pos):
+                offset += offsets[i]
+            device = mask.mask_index[dim].device
+            new_mask = mask.mask_index[dim] + offset
+            module_masks.output_mask.mask_index[dim] = CoarseMask.merge_index(
+                module_masks.output_mask.mask_index[dim], new_mask).to(device)
+        else:
+            assert module_masks.output_mask.eq_on_dim(mask, dim)
+
+    return module_masks.output_mask
+
+
+def add_inshape(module_masks, mask):
+    """
+    Inference the output mask of the add operation from the
+    input mask.
+    """
+    assert isinstance(mask, CoarseMask)
+    if module_masks.input_mask is None:
+        module_masks.set_input_mask(mask)
+        module_masks.set_output_mask(mask)
+        # module_masks.input_mask = mask
+        return mask
+    # If alreay visited, validate if have the conflict
+    # if the mask is different with previous input_mask
+    # then there is a mask confilct.
+    if mask != module_masks.input_mask:
+        raise Exception('Mask conflict happenes!')
+    return None
+
+
 def batchnorm2d_inshape(module_masks, mask):
     """
     We assume only the second dimension has coarse grained mask
@@ -199,6 +393,7 @@ def batchnorm2d_inshape(module_masks, mask):
     module_masks.set_param_masks('bias', weight_cmask)
     return mask
 
+
 def linear_inshape(module_masks, mask):
     """
     Coarse grained input mask does not change the shape of weights and output tensor
@@ -221,6 +416,7 @@ def linear_inshape(module_masks, mask):
     module_masks.set_input_mask(mask)
     return None
 
+
 def view_inshape(module_masks, mask, shape):
     """
     This is a limited support
@@ -246,7 +442,8 @@ def view_inshape(module_masks, mask, shape):
     assert shape['in_shape'][0] == shape['out_shape'][0]
     assert len(shape['in_shape']) == 4
     assert len(shape['out_shape']) == 2
-    assert shape['out_shape'][1] == shape['in_shape'][1]*shape['in_shape'][2]*shape['in_shape'][3]
+    assert shape['out_shape'][1] == shape['in_shape'][1] * \
+        shape['in_shape'][2]*shape['in_shape'][3]
 
     assert isinstance(mask, CoarseMask)
     assert mask.mask_index[1] is not None
@@ -260,7 +457,7 @@ def view_inshape(module_masks, mask, shape):
     step_size = shape['in_shape'][2] * shape['in_shape'][3]
     for loc in mask.mask_index[1]:
         index.extend([loc * step_size + i for i in range(step_size)])
-    output_cmask.add_index_mask(dim=1, index=torch.tensor(index)) # pylint: disable=not-callable
+    output_cmask.add_index_mask(dim=1, index=torch.tensor(index))  # pylint: disable=not-callable
     module_masks.set_output_mask(output_cmask)
     return output_cmask
 
@@ -271,6 +468,28 @@ def size_inshape(module_masks, mask):
     """
     return None
 
+def mean_inshape(module_masks, mask, shape):
+    """
+    Similar to view operation, currently mask inference only supports
+    the mean operation on the 3rd and 4th dimensions.
+    """
+    assert shape['in_shape'][0] == shape['out_shape'][0]
+    assert shape['out_shape'][1] == shape['in_shape'][1]
+    assert len(shape['in_shape']) == 4
+    assert len(shape['out_shape']) == 2
+
+    assert isinstance(mask, CoarseMask)
+    assert mask.mask_index[1] is not None
+    assert mask.mask_index[0] is None
+    assert mask.mask_index[2] is None
+    assert mask.mask_index[3] is None
+    module_masks.set_input_mask(mask)
+
+    output_cmask = CoarseMask(num_dim=2)
+    output_cmask.add_index_mask(dim=1, index=mask.mask_index[1])
+    module_masks.set_output_mask(output_cmask)
+    return output_cmask
+
 def maxpool2d_inshape(module_masks, mask):
     """
     Assume only the second dimension is masked
@@ -292,11 +511,14 @@ def maxpool2d_inshape(module_masks, mask):
     assert mask.mask_index[0] is None
     assert mask.mask_index[2] is None
     assert mask.mask_index[3] is None
-    assert module_masks.input_mask is None
+    if module_masks.input_mask is not None:
+        assert module_masks.input_mask <= mask
+    # assert module_masks.input_mask is None
     module_masks.set_input_mask(mask)
     module_masks.set_output_mask(mask)
     return mask
 
+
 def relu_inshape(module_masks, mask):
     """
     Parameters
@@ -313,11 +535,17 @@ def relu_inshape(module_masks, mask):
     """
     assert isinstance(mask, CoarseMask)
     # TODO: double check this assert, is it possible that a module is passed twice
-    assert module_masks.input_mask is None, "A relu op can only be processed once"
+    if module_masks.input_mask is not None:
+        # check if has a mask conflict
+        assert module_masks.input_mask == mask
+        # No need to pass the mask again
+        return None
+    # assert module_masks.input_mask is None, "A relu op can only be processed once"
     module_masks.set_input_mask(mask)
     module_masks.set_output_mask(mask)
     return mask
 
+
 def batchnorm2d_mask(module_masks, mask):
     """
     Infer input and output shape from weight mask
@@ -353,6 +581,7 @@ def batchnorm2d_mask(module_masks, mask):
     module_masks.set_output_mask(output_cmask)
     return input_cmask, output_cmask
 
+
 def conv2d_mask(module_masks, mask):
     """
     Infer input and output shape from weight mask
@@ -429,6 +658,7 @@ def convert_to_coarse_mask(mask):
         module_masks.output_mask.merge(output_cmask)
     return None, module_masks.output_mask
 
+
 def conv2d_inshape(module_masks, mask):
     """
     Shape change of input tensor does not affect the shape of its output tensor
@@ -446,10 +676,16 @@ def conv2d_inshape(module_masks, mask):
         The mask of its output tensor
     """
     assert isinstance(mask, CoarseMask)
-    assert module_masks.input_mask is None
-    module_masks.set_input_mask(mask)
+    if module_masks.input_mask is None:
+        module_masks.set_input_mask(mask)
+    else:
+        # the same conv layer may be accessed more
+        # than once, such as a concat operation.
+        assert module_masks.input_mask <= mask
+        module_masks.input_mask.merge(mask)
     return None
 
+
 def conv2d_outshape(module_masks, mask):
     """
     Assume only the second dimension is masked
@@ -487,4 +723,3 @@ def conv2d_outshape(module_masks, mask):
     module_masks.set_param_masks('bias', bias_cmask)
     # input shape is not changed
     return None
-    
\ No newline at end of file
diff --git a/src/sdk/pynni/nni/compression/torch/utils/mask_conflict.py b/src/sdk/pynni/nni/compression/torch/utils/mask_conflict.py
index 626283d43d..28412b1d9f 100644
--- a/src/sdk/pynni/nni/compression/torch/utils/mask_conflict.py
+++ b/src/sdk/pynni/nni/compression/torch/utils/mask_conflict.py
@@ -1,51 +1,231 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT license.
+import os
 import logging
 import torch
 import numpy as np
-from .shape_dependency import ChannelDependency
+from .shape_dependency import ChannelDependency, GroupDependency, CatPaddingDependency
 # logging.basicConfig(level = logging.DEBUG)
 _logger = logging.getLogger('FixMaskConflict')
 
-class MaskConflict:
-    def __init__(self, mask_file, model=None, dummy_input=None, graph=None):
+def fix_mask_conflict(masks, model=None, dummy_input=None, traced=None):
+    """
+    MaskConflict fix the mask conflict for the channel dependencies
+    and group dependency.
+
+    Parameters
+    ----------
+    masks : dict/str
+        A dict object that stores the masks or the path of the mask file
+    model : torch.nn.Module
+        model to fix the mask conflict
+    dummy_input : torch.Tensor
+        input example to trace the model
+    traced : torch._C.torch.jit.TopLevelTracedModule
+        the traced model of the target model, is this parameter is not None,
+        we donnot use the model and dummpy_input to get the trace graph.
+    """
+    if isinstance(masks, str):
+        # if the input is the path of the mask_file
+        assert os.path.exists(masks)
+        masks = torch.load(masks)
+    # if the user uses the model and dummy_input to trace the model, we
+    # should get the traced model handly, so that, we only trace the
+    # model once, GroupMaskConflict and ChannelMaskConflict will reuse
+    # this traced model.
+    if traced is None:
+        assert model is not None and dummy_input is not None
+        with torch.onnx.set_training(model, False):
+            # We need to trace the model in this way, else it will have problems
+            traced = torch.jit.trace(model, dummy_input)
+
+    fix_group_mask = GroupMaskConflict(masks, model, dummy_input, traced)
+    masks = fix_group_mask.fix_mask()
+    fix_channel_mask = ChannelMaskConflict(masks, model, dummy_input, traced)
+    masks = fix_channel_mask.fix_mask()
+    padding_cat_mask = CatMaskPadding(masks, model, dummy_input, traced)
+    masks = padding_cat_mask.fix_mask()
+    return masks
+
+class MaskFix:
+    def __init__(self, masks, model=None, dummy_input=None, traced=None):
+        # check if the parameters are valid
+        parameter_valid = False
+        if traced is not None:
+            parameter_valid = True
+        elif (model is not None) and (dummy_input is not None):
+            parameter_valid = True
+        if not parameter_valid:
+            raise Exception('The input parameters is invalid!')
+        self.model = model
+        self.dummy_input = dummy_input
+        self.traced = traced
+        self.masks = masks
+
+    def fix_mask(self):
+        raise NotImplementedError
+
+    def export(self, path):
+        """
+        Export the masks after fixing the conflict to file.
+        """
+        torch.save(self.masks, path)
+
+class CatMaskPadding(MaskFix):
+    def __init__(self, masks, model, dummy_input=None, traced=None):
+        """
+        CatMaskPadding find the layers whose output tensor is passed
+        to the same cat operation. The cat operation concatnates the
+        masks of the input tensors as the output mask, so when some
+        of the input layers of the cat operation are not pruned, we still
+        need to pass the masks of these non-pruned layers(the mask are
+        all ones) to the cat operation to ensure the shape of the output
+        mask is right.
+
+        Parameters
+        ----------
+        masks : dict
+            a dict object that stores the masks
+        model : torch.nn.Module
+            model to fix the mask conflict
+        dummy_input : torch.Tensor
+            input example to trace the model
+        traced : torch._C.torch.jit.TopLevelTracedModule
+            the traced model of the target model, is this parameter is not None,
+            we donnot use the model and dummpy_input to get the trace graph.
+        """
+        super(CatMaskPadding, self).__init__(masks, model, dummy_input, traced)
+
+    def fix_mask(self):
+        cat_padding_depen = CatPaddingDependency(self.model, self.dummy_input, self.traced)
+        name_to_module = {}
+        for name, module in self.model.named_modules():
+            name_to_module[name] = module
+        depen = cat_padding_depen.dependency_sets
+        for layers in depen:
+            device = None
+            count = 0
+            for layer in layers:
+                if layer in self.masks:
+                    count += 1
+                    if device is None:
+                        device = self.masks[layer]['weight'].device
+            if count == 0:
+                # no layer is pruned
+                continue
+            elif count == len(layers):
+                # all the layers have been pruned
+                continue
+            # pad the mask for the non-pruned layers
+            for layer in layers:
+                module = name_to_module[layer]
+                w_shape = module.weight.data.size()
+                w_mask = torch.ones(w_shape).to(device)
+                b_mask = None
+                if hasattr(module, 'bias'):
+                    b_shape = module.bias.data.size()
+                    b_mask = torch.ones(b_shape).to(device)
+                self.masks[layer] = {'weight':w_mask, 'bias':b_mask}
+        return self.masks
+
+
+
+class GroupMaskConflict(MaskFix):
+    def __init__(self, masks, model=None, dummy_input=None, traced=None):
+        """
+        GroupMaskConflict fix the mask conflict between the layers that
+        has group dependecy with each other.
+
+        Parameters
+        ----------
+        masks : dict
+            a dict object that stores the masks
+        model : torch.nn.Module
+            model to fix the mask conflict
+        dummy_input : torch.Tensor
+            input example to trace the model
+        traced : torch._C.torch.jit.TopLevelTracedModule
+            the traced model of the target model, is this parameter is not None,
+            we donnot use the model and dummpy_input to get the trace graph.
+        """
+        super(GroupMaskConflict, self).__init__(masks, model, dummy_input, traced)
+
+
+    def fix_mask(self):
+        """
+        Fix the mask conflict before the mask inference for the layers that
+        has group dependencies. This function should be called before the
+        mask inference of the 'speedup' module.
+        """
+        group_depen = GroupDependency(self.model, self.dummy_input, self.traced)
+        depens = group_depen.dependency
+        _logger.info(depens)
+        for layername in depens:
+            group = depens[layername]
+            if layername not in self.masks:
+                # this layer not pruned
+                continue
+            w_mask = self.masks[layername]['weight']
+            shape = w_mask.size()
+            count = np.prod(shape[1:])
+            all_ones = (w_mask.flatten(1).sum(-1) == count).nonzero().squeeze(1).tolist()
+            all_zeros = (w_mask.flatten(1).sum(-1) == 0).nonzero().squeeze(1).tolist()
+            if len(all_ones) + len(all_zeros) < w_mask.size(0):
+                # In fine-grained pruning, skip this layer
+                _logger.info('Layers %s using fine-grained pruning', layername)
+                continue
+            assert shape[0] % group == 0
+            # Find the number of masked filter for each group (mini_masked).
+            # Because we have to keep the pruned filter can still
+            # be divided into the same number of groups, so we only can
+            # prune mini_masked filters for each group.
+            step = shape[0] / group
+            group_masked = []
+            for i in range(group):
+                _start = step * i
+                _end = step * (i+1)
+                _tmp_list = list(filter(lambda x: _start <= x and x < _end, all_zeros))
+                group_masked.append(_tmp_list)
+            mini_masked = min([len(x) for x in group_masked])
+            for gm in group_masked:
+                for i in range(mini_masked, len(gm)):
+                    # To keep the output channel number still being divisible to
+                    # groups, we set the masks of following filters to be zero.
+                    pos = gm[i]
+                    self.masks[layername]['weight'][pos] = torch.ones(shape[1:])
+                    if hasattr(self.masks[layername], 'bias'):
+                        self.masks[layername]['bias'][pos] = 1
+        return self.masks
+
+
+
+class ChannelMaskConflict(MaskFix):
+    def __init__(self, masks, model=None, dummy_input=None, traced=None):
         """
-        MaskConflict fix the mask conflict between the layers that
+        ChannelMaskConflict fix the mask conflict between the layers that
         has channel dependecy with each other.
 
         Parameters
         ----------
+        masks : dict
+            a dict object that stores the masks
         model : torch.nn.Module
             model to fix the mask conflict
         dummy_input : torch.Tensor
             input example to trace the model
-        mask_file : str
-            the path of the original mask file
-        graph : torch._C.Graph
+        graph : torch._C.torch.jit.TopLevelTracedModule
             the traced graph of the target model, is this parameter is not None,
             we donnot use the model and dummpy_input to get the trace graph.
         """
-        # check if the parameters are valid
-        parameter_valid = False
-        if graph is not None:
-            parameter_valid = True
-        elif (model is not None) and (dummy_input is not None):
-            parameter_valid = True
-        if not parameter_valid:
-            raise Exception('The input parameters is invalid!')
-        self.model = model
-        self.dummy_input = dummy_input
-        self.graph = graph
-        self.mask_file = mask_file
-        self.masks = torch.load(self.mask_file)
+        super(ChannelMaskConflict, self).__init__(masks, model, dummy_input, traced)
 
-    def fix_mask_conflict(self):
+    def fix_mask(self):
         """
         Fix the mask conflict before the mask inference for the layers that
         has shape dependencies. This function should be called before the
         mask inference of the 'speedup' module.
         """
-        channel_depen = ChannelDependency(self.model, self.dummy_input, self.graph)
+        channel_depen = ChannelDependency(self.model, self.dummy_input, self.traced)
         depen_sets = channel_depen.dependency_sets
         for dset in depen_sets:
             if len(dset) == 1:
@@ -53,11 +233,18 @@ def fix_mask_conflict(self):
                 continue
             channel_remain = set()
             fine_grained = False
+            out_channels = None
+            # A flag that represents if all the layers in
+            # the dependency set are pruned
+            all_pruned = True
             for name in dset:
                 if name not in self.masks:
                     # this layer is not pruned
+                    all_pruned = False
                     continue
                 w_mask = self.masks[name]['weight']
+                if out_channels is None:
+                    out_channels = w_mask.size(0)
                 shape = w_mask.size()
                 count = np.prod(shape[1:])
                 all_ones = (w_mask.flatten(1).sum(-1) == count).nonzero().squeeze(1).tolist()
@@ -74,8 +261,19 @@ def fix_mask_conflict(self):
             # Update the masks for the layers in the dependency set
             if fine_grained:
                 continue
+            if not all_pruned:
+                # if some layer are not pruned at all
+                # then all the layers in this dependency set
+                # cannot be pruned due to the shape dependency.
+                channel_remain.update(range(out_channels))
             ori_channels = 0
             for name in dset:
+                if name not in self.masks:
+                    # this layer is not pruned at all
+                    # in this case, all_pruned is False
+                    # and the other layers in the same dset
+                    # will not be pruned either.
+                    continue
                 mask = self.masks[name]
                 w_shape = mask['weight'].size()
                 ori_channels = w_shape[0]
@@ -88,9 +286,3 @@ def fix_mask_conflict(self):
             pruned_filters = set(list(range(ori_channels)))-channel_remain
             _logger.info(str(sorted(pruned_filters)))
         return self.masks
-
-    def export(self, path):
-        """
-        Export the masks after fixing the conflict to file.
-        """
-        torch.save(self.masks, path)
diff --git a/src/sdk/pynni/nni/compression/torch/utils/shape_dependency.py b/src/sdk/pynni/nni/compression/torch/utils/shape_dependency.py
index 8922ec483e..49aa32b7c9 100644
--- a/src/sdk/pynni/nni/compression/torch/utils/shape_dependency.py
+++ b/src/sdk/pynni/nni/compression/torch/utils/shape_dependency.py
@@ -6,6 +6,7 @@
 
 from nni._graph_utils import TorchModuleGraph
 
+__all__ = ['ChannelDependency', 'GroupDependency', 'CatPaddingDependency']
 
 CONV_TYPE = 'aten::_convolution'
 ADD_TYPES = ['aten::add', 'aten::add_']
@@ -13,7 +14,27 @@
 logger = logging.getLogger('Shape_Dependency')
 
 
-class ChannelDependency:
+class Dependency:
+    def __init__(self, model=None, dummy_input=None, traced_model=None):
+        """
+        Build the graph for the model.
+        """
+        # check if the input is legal
+        if traced_model is None:
+            # user should provide model & dummy_input to trace
+            # the model or a already traced model
+            assert model is not None and dummy_input is not None
+        self.graph = TorchModuleGraph(model, dummy_input, traced_model)
+        self.dependency = dict()
+        self.build_dependency()
+
+    def build_dependency(self):
+        raise NotImplementedError
+
+    def export(self, filepath):
+        raise NotImplementedError
+
+class ChannelDependency(Dependency):
     def __init__(self, model=None, dummy_input=None, traced_model=None):
         """
         This model analyze the channel dependencis between the conv
@@ -29,13 +50,7 @@ def __init__(self, model=None, dummy_input=None, traced_model=None):
             if we alreay has the traced graph of the target model, we donnot
             need to trace the model again.
         """
-        # check if the input is legal
-        if traced_model is None:
-            # user should provide model & dummy_input to trace the model or a already traced model
-            assert model is not None and dummy_input is not None
-        self.graph = TorchModuleGraph(model, dummy_input, traced_model)
-        self.dependency = dict()
-        self.build_channel_dependency()
+        super(ChannelDependency, self).__init__(model, dummy_input, traced_model)
 
     def _get_parent_layers(self, node):
         """
@@ -66,7 +81,7 @@ def _get_parent_layers(self, node):
                 queue.append(parent)
         return parent_layers
 
-    def build_channel_dependency(self):
+    def build_dependency(self):
         """
         Build the channel dependency for the conv layers
         in the model.
@@ -119,7 +134,7 @@ def export(self, filepath):
         Set 2,layer1.0.conv1
         Set 3,layer1.1.conv1
         """
-        header = ['Dependency Set', 'Convolutional Layers']
+        header = ['Dependency Set', 'Layers']
         setid = 0
         visited = set()
         with open(filepath, 'w') as csvf:
@@ -166,3 +181,200 @@ def dependency_sets(self):
                     tmp_set.add(other)
             d_sets.append(tmp_set)
         return d_sets
+
+class CatPaddingDependency(ChannelDependency):
+    def __init__(self, model=None, dummy_input=None, traced_model=None):
+        super(CatPaddingDependency, self).__init__(model, dummy_input, traced_model)
+
+    def build_dependency(self):
+        """
+        Build the cat padding dependencies.
+        If the output features of several layers are stitched together
+        by cat operation, then these layers have cat padding dependencies.
+        This is because when inferring the cat mask, we need all the input
+        masks for the cat operation. At this time we need to know the source
+        of all input vectors of a cat operation.
+        """
+        for node in self.graph.nodes_py.nodes_op:
+            parent_layers = []
+            if node.op_type == CAT_TYPE:
+                parent_layers = self._get_parent_layers(node)
+                dependency_set = set(parent_layers)
+                # merge the dependencies
+                for parent in parent_layers:
+                    if parent in self.dependency:
+                        dependency_set.update(self.dependency[parent])
+                # save the dependencies
+                for _node in dependency_set:
+                    self.dependency[_node] = dependency_set
+
+    @property
+    def dependency_sets(self):
+        d_sets = []
+        visited = set()
+        for nodename in self.dependency:
+            if nodename in visited:
+                continue
+            d_sets.append(self.dependency[nodename])
+        return d_sets
+
+    def export(self, filepath):
+        """
+        Export the dependencies into a file.
+        In the output file, each line contains a set of layers
+        whose output features are stitched together by the cat
+        operation.
+
+        output example:
+        Dependency Set, Layers
+        set1, Conv1, Conv2
+        set2, Conv3, Conv4
+        """
+        header = ['Dependency Set', 'Layers']
+        setid = 0
+        with open(filepath, 'w') as csvf:
+            csv_w = csv.writer(csvf, delimiter=',')
+            csv_w.writerow(header)
+            for layers in self.dependency_sets:
+                setid += 1
+                row = ['Set %d' % setid]
+                row.extend(list(layers))
+                csv_w.writerow(row)
+
+class GroupDependency(Dependency):
+    def __init__(self, model=None, dummy_input=None, traced_model=None):
+        """
+        This model analyze the group dependencis between the conv
+        layers in a model.
+
+        Parameters
+        ----------
+        model : torch.nn.Module
+            The model to be analyzed.
+        data : torch.Tensor
+            The example input data to trace the network architecture.
+        traced_model : torch._C.Graph
+            if we alreay has the traced graph of the target model, we donnot
+            need to trace the model again.
+        """
+        super(GroupDependency, self).__init__(model, dummy_input, traced_model)
+
+    def _get_parent_convs(self, node):
+        """
+        Find the nearest father conv layers for the target node.
+
+        Parameters
+        ---------
+        node : torch._C.Node
+            target node.
+
+        Returns
+        -------
+        parent_layers : list
+            nearest father conv layers for the target node. Due to the group
+            dependency only exists between the conv layers, so we only find
+            the parent conv layers.
+        """
+        parent_layers = []
+        # the input node is a Conv node
+        predeessors = self.graph.find_predecessors(node.unique_name)
+        predeessors = [self.graph.name_to_node[x] for x in predeessors]
+        queue = predeessors
+        while queue:
+            curnode = queue.pop(0)
+            if curnode.op_type == 'Conv2d':
+                # find the first met conv
+                parent_layers.append(curnode.name)
+                continue
+            parents = self.graph.find_predecessors(curnode.unique_name)
+            parents = [self.graph.name_to_node[name] for name in parents]
+            for parent in parents:
+                queue.append(parent)
+        return parent_layers
+
+    def _get_conv_groups(self, node_group):
+        """
+        Get the number of groups for a convolutional layer.
+
+        Parameters
+        ----------
+        node_group : NodePyGroup
+            target node.
+
+        Returns
+        -------
+        group : int
+            the number of the groups of the target conv layer.
+        """
+        cpp_conv = list(filter(lambda x: x.kind() == CONV_TYPE, node_group.node_cpps))
+        assert len(cpp_conv) == 1
+        cpp_conv = cpp_conv[0]
+        inputs = list(cpp_conv.inputs())
+        # get the number of the group from the input parameters
+        group = inputs[8].toIValue()
+        return group
+
+    def build_dependency(self):
+        """
+        Build the channel dependency for the conv layers
+        in the model. This function return the group number
+        of each conv layers. Note that, here, the group count
+        of conv layers may be larger than their originl groups.
+        This is because that the input channel will also be grouped
+        for the group conv layers. To make this clear, assume we
+        have two group conv layers: conv1(group=2), conv2(group=4).
+        conv2 takes the output features of conv1 as input.
+        Then we have to the filters of conv1 can still be
+        divided into 4 groups after filter pruning, because
+        the input channels of conv2 shoule be divided into
+        4 groups.
+
+        Returns
+        -------
+        self.dependency : dict
+            key: the name of conv layers, value: the minimum value that the number of
+            filters should be divisible to.
+        """
+        for node in self.graph.nodes_py.nodes_op:
+            if node.op_type == 'Conv2d':
+                group = self._get_conv_groups(node)
+                if node.name in self.dependency:
+                    # the conv layer whose group is larger than 1 will require that
+                    # it's number of output channel to be divisible by the number of group.
+                    self.dependency[node.name] = max(self.dependency[node.name], group)
+                else:
+                    self.dependency[node.name] = group
+                if group > 1:
+                    # for the conv layer whose group is larger than 1, it will require the number
+                    # of output channels of their parent conv layer to be divisible by group.
+                    parent_convs = self._get_parent_convs(node)
+                    for parent in parent_convs:
+                        if parent in self.dependency:
+                            self.dependency[parent] = max(self.dependency[parent], group)
+                        else:
+                            self.dependency[parent] = group
+        return self.dependency
+
+    def export(self, filepath):
+        """
+        export the group dependency to a csv file.
+        Each line describes a convolution layer, the
+        first part of each line is the Pytorch module
+        name of the conv layer. The second part of each
+        line is the group count of the filters in this layer.
+        Note that, the group count may be larger than this
+        layers original group number.
+
+        output example:
+        Conv layer, Groups
+        Conv1, 1
+        Conv2, 2
+        Conv3, 4
+        """
+        header = ['Conv Layer Name', 'Group']
+        with open(filepath, 'w') as csvf:
+            csv_w = csv.writer(csvf, delimiter=',')
+            csv_w.writerow(header)
+            for name in self.dependency:
+                group = self.dependency[name]
+                csv_w.writerow([name, group])
diff --git a/src/sdk/pynni/tests/test_compression_utils.py b/src/sdk/pynni/tests/test_compression_utils.py
index 803666a50c..90c88db573 100644
--- a/src/sdk/pynni/tests/test_compression_utils.py
+++ b/src/sdk/pynni/tests/test_compression_utils.py
@@ -11,13 +11,13 @@
 
 from nni.compression.torch import L1FilterPruner
 from nni.compression.torch.utils.shape_dependency import ChannelDependency
-from nni.compression.torch.utils.mask_conflict import MaskConflict
+from nni.compression.torch.utils.mask_conflict import fix_mask_conflict
 
 device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')
 prefix = 'analysis_test'
 model_names = ['alexnet', 'vgg11', 'vgg11_bn', 'vgg13', 'vgg19',
                'resnet18', 'resnet34', 'squeezenet1_1',
-               'shufflenet_v2_x1_0', 'mobilenet_v2', 'wide_resnet50_2']
+               'mobilenet_v2', 'wide_resnet50_2']
 
 channel_dependency_ground_truth = {
     'resnet18': [{'layer1.0.conv2', 'layer1.1.conv2', 'conv1'},
@@ -49,8 +49,12 @@
     'vgg13': [],
     'vgg19': [],
     'squeezenet1_1': [],
-    'googlenet': [],
-    'shufflenet_v2_x1_0': []
+    'googlenet': []
+    # comments the shufflenet temporary
+    # because it has the listunpack operation which
+    # will lead to a graph construction error.
+    # support the listunpack in the next release.
+    # 'shufflenet_v2_x1_0': []
 }
 
 unittest.TestLoader.sortTestMethodsUsing = None
@@ -111,9 +115,8 @@ def test_mask_conflict(self):
             pruner.export_model(ck_file, mask_file)
             pruner._unwrap_model()
             # Fix the mask conflict
-            mf = MaskConflict(mask_file, net, dummy_input)
-            fixed_mask = mf.fix_mask_conflict()
-            mf.export(os.path.join(outdir, '%s_fixed_mask' % name))
+            fixed_mask = fix_mask_conflict(mask_file, net, dummy_input)
+
             # use the channel dependency groud truth to check if
             # fix the mask conflict successfully
             for dset in channel_dependency_ground_truth[name]:
diff --git a/src/sdk/pynni/tests/test_model_speedup.py b/src/sdk/pynni/tests/test_model_speedup.py
index e33bd70b10..a06f991c97 100644
--- a/src/sdk/pynni/tests/test_model_speedup.py
+++ b/src/sdk/pynni/tests/test_model_speedup.py
@@ -4,6 +4,7 @@
 import os
 import numpy as np
 import torch
+import torchvision.models as models
 import torch.nn as nn
 import torch.nn.functional as F
 from torchvision.models.vgg import vgg16
@@ -13,7 +14,17 @@
 from nni.compression.torch import L1FilterPruner, apply_compression_results, ModelSpeedup
 
 torch.manual_seed(0)
-
+device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')
+BATCH_SIZE = 2
+# the relative distance
+RELATIVE_THRESHOLD = 0.01
+# Because of the precision of floating-point numbers, some errors
+# between the original output tensors(without speedup) and the output
+# tensors of the speedup model are normal. When the output tensor itself
+# is small, such errors may exceed the relative threshold, so we also add
+# an absolute threshold to determine whether the final result is correct.
+# The error should meet the RELATIVE_THREHOLD or the ABSOLUTE_THRESHOLD.
+ABSOLUTE_THRESHOLD = 0.0001
 class BackboneModel1(nn.Module):
     def __init__(self):
         super().__init__()
@@ -72,6 +83,27 @@ def prune_model_l1(model):
     pruner.compress()
     pruner.export_model(model_path=MODEL_FILE, mask_path=MASK_FILE)
 
+def generate_random_sparsity(model):
+    cfg_list = []
+    for name, module in model.named_modules():
+        if isinstance(module, nn.Conv2d):
+            sparsity = np.random.uniform(0.5, 0.99)
+            cfg_list.append({'op_types': ['Conv2d'], 'op_names': [name],
+                             'sparsity': sparsity})
+    return cfg_list
+
+def zero_bn_bias(model):
+    with torch.no_grad():
+        for name, module in model.named_modules():
+            if isinstance(module, nn.BatchNorm2d) \
+            or isinstance(module, nn.BatchNorm3d) \
+            or isinstance(module, nn.BatchNorm1d):
+                shape = module.bias.data.size()
+                device = module.bias.device
+                module.bias.data = torch.zeros(shape).to(device)
+                shape = module.running_mean.data.size()
+                module.running_mean = torch.zeros(shape).to(device)
+
 class SpeedupTestCase(TestCase):
     def test_speedup_vgg16(self):
         prune_model_l1(vgg16())
@@ -85,10 +117,6 @@ def test_speedup_vgg16(self):
         assert model.features[2].out_channels == int(orig_model.features[2].out_channels * SPARSITY)
         assert model.classifier[0].in_features == int(orig_model.classifier[0].in_features * SPARSITY)
 
-    #def test_speedup_resnet(self):
-        #TODO support resnet
-        #model = resnet18()
-
     def test_speedup_bigmodel(self):
         prune_model_l1(BigModel())
         model = BigModel()
@@ -116,6 +144,36 @@ def test_speedup_bigmodel(self):
         assert model.backbone2.conv2.out_channels == int(orig_model.backbone2.conv2.out_channels * SPARSITY)
         assert model.backbone2.fc1.in_features == int(orig_model.backbone2.fc1.in_features * SPARSITY)
 
+    def test_speedup_integration(self):
+        for model_name in ['resnet18', 'squeezenet1_1', 'mobilenet_v2']:
+            Model = getattr(models, model_name)
+            net = Model(pretrained=True, progress=False).to(device)
+            net.eval() # this line is necessary
+            # random generate the prune config for the pruner
+            cfgs = generate_random_sparsity(net)
+            pruner = L1FilterPruner(net, cfgs)
+            pruner.compress()
+            pruner.export_model(MODEL_FILE, MASK_FILE)
+            pruner._unwrap_model()
+            speedup_model = Model().to(device)
+            speedup_model.eval()
+            state_dict = torch.load(MODEL_FILE)
+            speedup_model.load_state_dict(state_dict)
+            zero_bn_bias(net)
+            zero_bn_bias(speedup_model)
+
+            data = torch.ones(BATCH_SIZE, 3, 224, 224).to(device)
+            ms = ModelSpeedup(speedup_model, data, MASK_FILE)
+            ms.speedup_model()
+            ori_out = net(data)
+            speeded_out = speedup_model(data)
+            ori_sum = torch.sum(ori_out).item()
+            speeded_sum = torch.sum(speeded_out).item()
+            print('Sum of the output of %s (before speedup):'%model_name, ori_sum)
+            print('Sum of the output of %s (after speedup):'%model_name, speeded_sum)
+            assert (abs(ori_sum - speeded_sum) / abs(ori_sum) < RELATIVE_THRESHOLD) or \
+                   (abs(ori_sum - speeded_sum) < ABSOLUTE_THRESHOLD)
+
     def tearDown(self):
         os.remove(MODEL_FILE)
         os.remove(MASK_FILE)