diff --git a/python/paddle_serving_app/trace.py b/python/paddle_serving_app/trace.py
index 83473c22660a7b789424e905f8f399ea2cfe00b1..2a7f35b672d8d9bd7e9b8c64c5004eca7b9f6795 100644
--- a/python/paddle_serving_app/trace.py
+++ b/python/paddle_serving_app/trace.py
@@ -1,4 +1,20 @@
-#coding=utf-8
+# -*- coding: utf-8 -*-
+"""
+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""
+
 import json
 import sys
 import argparse