diff --git a/python/oneflow/framework/check_point_v2.py b/python/oneflow/framework/check_point_v2.py
index 2b0678dd2e9..2ae64998163 100644
--- a/python/oneflow/framework/check_point_v2.py
+++ b/python/oneflow/framework/check_point_v2.py
@@ -703,6 +703,12 @@ def save(
     """
     if isinstance(path_or_buffer, str):
         path_or_buffer = Path(path_or_buffer)
+    if os.path.isdir(path_or_buffer) and not save_as_external_data:
+        path_or_buffer = path_or_buffer / "model.of"
+    warnings.warn(
+        f"The save path cannot be a dir name from oneflow-0.9.1! The system "
+        f"will automatically complete it into the file name as {path_or_buffer}"
+    )
 
     if isinstance(obj, graph_util.Graph):
         if not _is_path(path_or_buffer):