diff --git a/docs/zh-CN/sql-reference/sql-functions/string-functions/substring.md b/docs/zh-CN/sql-reference/sql-functions/string-functions/substring.md
index cdbbc2b056..c56bc989fa 100644
--- a/docs/zh-CN/sql-reference/sql-functions/string-functions/substring.md
+++ b/docs/zh-CN/sql-reference/sql-functions/string-functions/substring.md
@@ -40,7 +40,7 @@ under the License.
 ## example
 
 ```
-mysql> select substring('abc1', -2);
+mysql> select substring('abc1', 2);
 +-----------------------------+
 | substring('abc1', 2)        |
 +-----------------------------+