diff --git a/5-enhance/5-3-easyuse-sql-compat-func-nvl.md b/5-enhance/5-3-easyuse-sql-compat-func-nvl.md
index 5681e14f88d274a484f3ac4e4aa62d335aae6c5d..48583c099ed7c914bdeda47fa5f6c9bfc39ad2e9 100644
--- a/5-enhance/5-3-easyuse-sql-compat-func-nvl.md
+++ b/5-enhance/5-3-easyuse-sql-compat-func-nvl.md
@@ -4,7 +4,7 @@
 ## 1. 语法
 
 ```sql
-NVL(expr1，expr2)
+NVL(expr1,expr2)
 ```
 
 ## 2. 定义和用法