diff --git a/docs/en/12-taos-sql/20-keywords.md b/docs/en/12-taos-sql/20-keywords.md
index 36cbc0948f..91be44c561 100644
--- a/docs/en/12-taos-sql/20-keywords.md
+++ b/docs/en/12-taos-sql/20-keywords.md
@@ -151,7 +151,7 @@ The following list shows all reserved keywords:
 - INTERVAL
 - INTO
 - IS
-- ISNULL
+- IS NULL
 
 ### J
 
@@ -197,7 +197,7 @@ The following list shows all reserved keywords:
 - NMATCH
 - NONE
 - NOT
-- NOTNULL
+- NOT NULL
 - NOW
 - NULL
 - NULLS
diff --git a/docs/zh/12-taos-sql/20-keywords.md b/docs/zh/12-taos-sql/20-keywords.md
index f59eda1689..4d2454ed5a 100644
--- a/docs/zh/12-taos-sql/20-keywords.md
+++ b/docs/zh/12-taos-sql/20-keywords.md
@@ -151,7 +151,7 @@ description: TDengine 保留关键字的详细列表
 - INTERVAL
 - INTO
 - IS
-- ISNULL
+- IS NULL
 
 ### J
 
@@ -197,7 +197,7 @@ description: TDengine 保留关键字的详细列表
 - NMATCH
 - NONE
 - NOT
-- NOTNULL
+- NOT NULL
 - NOW
 - NULL
 - NULLS