diff --git a/docs/comment.md b/docs/comment.md
index 0fc59c7..2955f77 100644
--- a/docs/comment.md
+++ b/docs/comment.md
@@ -185,6 +185,7 @@ function bar() {
 
 `@extends`命令用于定义继承的基类。
 
+```javascript
 /**
  * @extends {Base}
  */