diff --git a/src/spaceone/identity/service/user_profile_service.py b/src/spaceone/identity/service/user_profile_service.py
index ef50b62..4bab769 100644
--- a/src/spaceone/identity/service/user_profile_service.py
+++ b/src/spaceone/identity/service/user_profile_service.py
@@ -16,21 +16,23 @@
 from spaceone.identity.manager.mfa_manager.base import MFAManager
 from spaceone.identity.manager.role_binding_manager import RoleBindingManager
 from spaceone.identity.manager.role_manager import RoleManager
-from spaceone.identity.manager.token_manager.local_token_manager import \
-    LocalTokenManager
+from spaceone.identity.manager.token_manager.local_token_manager import (
+    LocalTokenManager,
+)
 from spaceone.identity.manager.user_manager import UserManager
-from spaceone.identity.manager.workspace_group_manager import \
-    WorkspaceGroupManager
+from spaceone.identity.manager.workspace_group_manager import WorkspaceGroupManager
 from spaceone.identity.manager.workspace_manager import WorkspaceManager
 from spaceone.identity.model.user.database import User
 from spaceone.identity.model.user.response import *
 from spaceone.identity.model.user_profile.request import *
-from spaceone.identity.model.user_profile.request import \
-    UserProfileGetWorkspaceGroupsRequest
+from spaceone.identity.model.user_profile.request import (
+    UserProfileGetWorkspaceGroupsRequest,
+)
 from spaceone.identity.model.user_profile.response import (
-    MyWorkspaceGroupsResponse, MyWorkspacesResponse)
-from spaceone.identity.service.workspace_group_service import \
-    WorkspaceGroupService
+    MyWorkspaceGroupsResponse,
+    MyWorkspacesResponse,
+)
+from spaceone.identity.service.workspace_group_service import WorkspaceGroupService
 
 _LOGGER = logging.getLogger(__name__)
 
@@ -463,7 +465,7 @@ def get_workspace_groups(
 
         workspace_group_user_ids = []
         for workspace_group_info in workspace_group_infos:
-            if users := workspace_group_info.users:
+            if users := workspace_group_info.get("users", []) or []:
                 for user in users:
                     if isinstance(user, dict):
                         workspace_group_user_ids.append(user.get("user_id"))
diff --git a/src/spaceone/identity/service/workspace_group_service.py b/src/spaceone/identity/service/workspace_group_service.py
index e8e729d..a05a342 100644
--- a/src/spaceone/identity/service/workspace_group_service.py
+++ b/src/spaceone/identity/service/workspace_group_service.py
@@ -535,7 +535,7 @@ def add_users_to_workspace_group(
     def add_user_name_and_state_to_users(
         self,
         workspace_group_user_ids: List[str],
-        workspace_group_info: WorkspaceGroup,
+        workspace_group_info: Union[WorkspaceGroup, Dict[str, str]],
         domain_id: str,
     ) -> Dict[str, str]:
         """Add user's name and state to users in workspace group.
@@ -543,11 +543,16 @@ def add_user_name_and_state_to_users(
         we need to add user's name and state to users in the Application layer.
         Args:
             workspace_group_user_ids: 'List[str]'
-            workspace_group_info: 'WorkspaceGroup'
+            workspace_group_info: 'Union[WorkspaceGroup, Dict[str, str]]'
             domain_id: 'str'
         Returns:
             workspace_group_dict:
         """
+        if isinstance(workspace_group_info, dict):
+            wg_users = workspace_group_info.get("users", [])
+        else:
+            wg_users = workspace_group_info.users or []
+
         user_vos = self.user_mgr.filter_users(
             user_id=workspace_group_user_ids, domain_id=domain_id
         )
@@ -559,18 +564,31 @@ def add_user_name_and_state_to_users(
                 "state": user_vo.state,
             }
 
-        wg_users = workspace_group_info.users or []
         users = []
-
         for user in wg_users:
-            user_id = user.user_id or ""
-            user.user_name = user_info_map.get(user_id, {}).get("name", "")
-            user.state = user_info_map.get(user_id, {}).get("state", "")
-            users.append(user)
+            if isinstance(user, dict):
+                user_id = user.get("user_id", "")
+            else:
+                user_id = getattr(user, "user_id", "") or ""
 
-        workspace_group_info["users"] = users
+            user_name = user_info_map.get(user_id, {}).get("name", "")
+            user_state = user_info_map.get(user_id, {}).get("state", "")
 
-        return workspace_group_info.to_dict()
+            if isinstance(user, dict):
+                user["user_name"] = user_name
+                user["state"] = user_state
+            else:
+                setattr(user, "user_name", user_name)
+                setattr(user, "state", user_state)
+
+            users.append(user)
+
+        if isinstance(workspace_group_info, dict):
+            workspace_group_info["users"] = users
+            return workspace_group_info
+        else:
+            workspace_group_info.users = users
+            return workspace_group_info.to_dict()
 
     def remove_users_from_workspace_group(
         self,