diff --git a/documentation/webdocs/markdowndocs/Super Table-ch.md b/documentation/webdocs/markdowndocs/Super Table-ch.md
index ee00eb1e869b0155657f89fc5a59650ca8ece9ba..0c55061324cdf383744bd632e2a400f8570c9e09 100644
--- a/documentation/webdocs/markdowndocs/Super Table-ch.md	
+++ b/documentation/webdocs/markdowndocs/Super Table-ch.md	
@@ -54,7 +54,7 @@ STable从属于库，一个STable只属于一个库，但一个库可以有一
     说明：
 
     1. TAGS列总长度不能超过512 bytes；
-    2. TAGS列的数据类型不能是timestamp和nchar类型；
+    2. TAGS列的数据类型不能是timestamp；
     3. TAGS列名不能与其他列名相同;
     4. TAGS列名不能为预留关键字. 
 
diff --git a/documentation/webdocs/markdowndocs/Super Table.md b/documentation/webdocs/markdowndocs/Super Table.md
index 85c840f77458f2bf83f51e3d687d15c6fc62858d..609dd11bd278da3398330fa33f857fac65ffb3d5 100644
--- a/documentation/webdocs/markdowndocs/Super Table.md	
+++ b/documentation/webdocs/markdowndocs/Super Table.md	
@@ -23,7 +23,7 @@ New keyword "tags" is introduced, where tag_name is the tag name, and tag_type i
 Note：
 
 1. The bytes of all tags together shall be less than 512 
-2. Tag's data type can not be time stamp or nchar
+2. Tag's data type can not be time stamp
 3. Tag name shall be different from the field name
 4. Tag name shall not be the same as system keywords
 5. Maximum number of tags is 6