diff --git a/src/main/java/clap/server/adapter/outbound/persistense/CategoryPersistenceAdapter.java b/src/main/java/clap/server/adapter/outbound/persistense/CategoryPersistenceAdapter.java
index e99883db..c34d1539 100644
--- a/src/main/java/clap/server/adapter/outbound/persistense/CategoryPersistenceAdapter.java
+++ b/src/main/java/clap/server/adapter/outbound/persistense/CategoryPersistenceAdapter.java
@@ -50,10 +50,17 @@ public List<Category> findSubCategory() {
     }
 
     @Override
-    public boolean existsByNameOrCode(String name, String code) {
-        return categoryRepository.existsByNameOrCodeAndIsDeletedFalse(name, code);
+    public boolean existsMainCategoryByNameOrCode(String name, String code) {
+        return categoryRepository.existsByNameOrCodeAndMainCategoryIsNullAndIsDeletedFalse(name, code);
     }
 
+    @Override
+    public boolean existsSubCategoryByNameOrCode(Category category, String name, String code) {
+        CategoryEntity categoryEntity = categoryPersistenceMapper.toEntity(category);
+        return categoryRepository.existsByMainCategoryAndIsDeletedFalseAndNameOrCode(categoryEntity, name, code);
+    }
+
+
     @Override
     public void save(final Category category) {
         categoryRepository.save(categoryPersistenceMapper.toEntity(category));
diff --git a/src/main/java/clap/server/adapter/outbound/persistense/repository/task/CategoryRepository.java b/src/main/java/clap/server/adapter/outbound/persistense/repository/task/CategoryRepository.java
index 5cdcc2b1..b2cdf46c 100644
--- a/src/main/java/clap/server/adapter/outbound/persistense/repository/task/CategoryRepository.java
+++ b/src/main/java/clap/server/adapter/outbound/persistense/repository/task/CategoryRepository.java
@@ -1,6 +1,8 @@
 package clap.server.adapter.outbound.persistense.repository.task;
 import clap.server.adapter.outbound.persistense.entity.task.CategoryEntity;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 import org.springframework.stereotype.Repository;
 
 import java.util.List;
@@ -12,5 +14,9 @@ public interface CategoryRepository extends JpaRepository<CategoryEntity, Long>
     List<CategoryEntity> findByIsDeletedFalseAndMainCategoryIsNull();
     List<CategoryEntity> findByIsDeletedFalseAndMainCategoryIsNotNull();
 
-    boolean existsByNameOrCodeAndIsDeletedFalse(String name, String code);
+    @Query("SELECT CASE WHEN COUNT(c) > 0 THEN true ELSE false END FROM CategoryEntity c WHERE c.mainCategory IS NULL AND c.isDeleted = false AND (c.name = :name OR c.code = :code)")
+    boolean existsByNameOrCodeAndMainCategoryIsNullAndIsDeletedFalse(@Param("name") String name, @Param("code") String code);
+
+    @Query("SELECT CASE WHEN COUNT(c) > 0 THEN true ELSE false END FROM CategoryEntity c WHERE c.mainCategory = :mainCategory AND c.isDeleted = false AND (c.name = :name OR c.code = :code)")
+    boolean existsByMainCategoryAndIsDeletedFalseAndNameOrCode(@Param("mainCategory")CategoryEntity mainCategory, @Param("name") String name, @Param("code") String code);
 }
\ No newline at end of file
diff --git a/src/main/java/clap/server/application/port/outbound/task/LoadCategoryPort.java b/src/main/java/clap/server/application/port/outbound/task/LoadCategoryPort.java
index 2533e8ff..9349f583 100644
--- a/src/main/java/clap/server/application/port/outbound/task/LoadCategoryPort.java
+++ b/src/main/java/clap/server/application/port/outbound/task/LoadCategoryPort.java
@@ -12,5 +12,7 @@ public interface LoadCategoryPort {
     List<Category> findMainCategory();
     List<Category> findSubCategory();
 
-    boolean existsByNameOrCode(String name, String code);
+    boolean existsMainCategoryByNameOrCode(String name, String code);
+
+    boolean existsSubCategoryByNameOrCode(Category category, String name, String code);
 }
diff --git a/src/main/java/clap/server/application/service/admin/AddCategoryService.java b/src/main/java/clap/server/application/service/admin/AddCategoryService.java
index 4b934dc4..ff2476cb 100644
--- a/src/main/java/clap/server/application/service/admin/AddCategoryService.java
+++ b/src/main/java/clap/server/application/service/admin/AddCategoryService.java
@@ -29,7 +29,7 @@ public class AddCategoryService implements AddMainCategoryUsecase, AddSubCategor
     @Transactional
     public void addMainCategory(Long adminId, String code, String name) {
         Optional<Member> activeMember = loadMemberPort.findActiveMemberById(adminId);
-        if (loadCategoryPort.existsByNameOrCode(name, code)) throw new ApplicationException(CATEGORY_DUPLICATE);
+        if (loadCategoryPort.existsMainCategoryByNameOrCode(name, code)) throw new ApplicationException(CATEGORY_DUPLICATE);
         Category mainCategory = Category.createMainCategory(
                 activeMember.orElseThrow(() -> new ApplicationException(ACTIVE_MEMBER_NOT_FOUND)),
                 code, name);
@@ -39,13 +39,11 @@ public void addMainCategory(Long adminId, String code, String name) {
     @Override
     @Transactional
     public void addSubCategory(Long adminId, Long mainCategoryId, String code, String name, String descriptionExample) {
-        Optional<Member> activeMember = loadMemberPort.findActiveMemberById(adminId);
-        Optional<Category> mainCategory = loadCategoryPort.findById(mainCategoryId);
-        if (loadCategoryPort.existsByNameOrCode(name, code)) throw new ApplicationException(CATEGORY_DUPLICATE);
-        Category subCategory = Category.createSubCategory(
-                activeMember.orElseThrow(() -> new ApplicationException(ACTIVE_MEMBER_NOT_FOUND)),
-                mainCategory.orElseThrow(() -> new ApplicationException(CATEGORY_NOT_FOUND)),
-                code, name, descriptionExample);
+        Member activeMember = loadMemberPort.findActiveMemberById(adminId).orElseThrow(() -> new ApplicationException(ACTIVE_MEMBER_NOT_FOUND));
+        Category mainCategory = loadCategoryPort.findById(mainCategoryId).orElseThrow(() -> new ApplicationException(CATEGORY_NOT_FOUND));
+
+        if (loadCategoryPort.existsSubCategoryByNameOrCode(mainCategory, name, code)) throw new ApplicationException(CATEGORY_DUPLICATE);
+        Category subCategory = Category.createSubCategory(activeMember, mainCategory,code, name, descriptionExample);
         commandCategoryPort.save(subCategory);
     }
 }
\ No newline at end of file
diff --git a/src/main/java/clap/server/application/service/admin/UpdateCategoryService.java b/src/main/java/clap/server/application/service/admin/UpdateCategoryService.java
index cae97710..4c06415b 100644
--- a/src/main/java/clap/server/application/service/admin/UpdateCategoryService.java
+++ b/src/main/java/clap/server/application/service/admin/UpdateCategoryService.java
@@ -26,9 +26,15 @@ public class UpdateCategoryService implements UpdateCategoryUsecase {
     @Transactional
     public void updateCategory(Long adminId, Long categoryId, String name, String code, String descriptionExample) {
         Member admin = loadMemberPort.findActiveMemberById(adminId).orElseThrow(() -> new ApplicationException(ACTIVE_MEMBER_NOT_FOUND));
-        if (loadCategoryPort.existsByNameOrCode(name, code)) throw new ApplicationException(CATEGORY_DUPLICATE);
-        Category category = loadCategoryPort.findById(categoryId)
-                .orElseThrow(() -> new ApplicationException(CATEGORY_NOT_FOUND));
+        Category category = loadCategoryPort.findById(categoryId).orElseThrow(() -> new ApplicationException(CATEGORY_NOT_FOUND));
+        boolean isDuplicate;
+        if (category.getMainCategory() == null) {
+            isDuplicate = loadCategoryPort.existsMainCategoryByNameOrCode(name, code);
+        } else {
+            isDuplicate = loadCategoryPort.existsSubCategoryByNameOrCode(category.getMainCategory(), name, code);
+        }
+        if (isDuplicate) throw new ApplicationException(CATEGORY_DUPLICATE);
+
         category.updateCategory(admin, name, code, descriptionExample);
         commandCategoryPort.save(category);
     }