diff --git a/docs/tutorial/serving.md b/docs/tutorial/serving.md
index 204730feeed9f706b4dc0b605245bc1487b289c0..d69dec50daca6db4098a4dfa67000515664271ee 100644
--- a/docs/tutorial/serving.md
+++ b/docs/tutorial/serving.md
@@ -15,7 +15,7 @@ PaddleHub Serving有两种启动方式，分别是使用命令行启动，以及
 #### 命令行命令启动
 启动命令
 ```shell
-$ hub serving start --modules [Module1==Version1, Module2==Version2, ...] \
+$ hub serving start --modules Module1==Version1 Module2==Version2 ... \
                     --port XXXX \
                     --use_gpu \
                     --use_multiprocess \