diff --git a/src/client/src/tscParseLineProtocol.c b/src/client/src/tscParseLineProtocol.c
index a2aaa0ac88d1d8bd40b9315f91c4291adb971e73..befbf80ad502296c114b535bff48a85349f9dee5 100644
--- a/src/client/src/tscParseLineProtocol.c
+++ b/src/client/src/tscParseLineProtocol.c
@@ -1927,6 +1927,7 @@ static int32_t parseSmlKey(TAOS_SML_KV *pKV, const char **index, SHashObj *pHash
 
   pKV->key = calloc(len + TS_ESCAPE_CHAR_SIZE + 1, 1);
   memcpy(pKV->key, key, len + 1);
+  strntolower_s(pKV->key, pKV->key, (int32_t)len);
   addEscapeCharToString(pKV->key, len);
   tscDebug("SML:0x%"PRIx64" Key:%s|len:%d", info->id, pKV->key, len);
   *index = cur + 1;
diff --git a/tests/pytest/insert/line_insert.py b/tests/pytest/insert/line_insert.py
index b9aa9d39997d1c031e2e867b274c172c8b672f3c..ff26483aeb323ebd309ba7a41e91ac860af9d222 100644
--- a/tests/pytest/insert/line_insert.py
+++ b/tests/pytest/insert/line_insert.py
@@ -93,6 +93,7 @@ class TDTestCase:
                                 "double,id=for,123=4i64,smallint=5f64,double=5f64,of=3i64,key=L\"passitagin_stf\",!@#$.%^&*()=false abc=false 1626006933664",
                                 "from,id=!@#$.%^,123=4i64,smallint=5f64,double=5f64,of=3i64,key=L\"passitagin_stf\",!@#$.%^&*()=false abc=false 1626006933674",
                                 "!@#$.%^&*(),id=none,123=4i64,smallint=5f64,double=5f64,of=3i64,key=L\"passitagin_stf\",!@#$.%^&*()=false abc=false 1626006933684",
+                                "STABLE,id=CREATE,123=4i64,smallint=5f64,DOUBLE=5f64,of=3i64,key=L\"passitagin_stf\",!@#$.%^&*()=false SELECT=false 1626006933684",
                                 ], TDSmlProtocolType.LINE.value, TDSmlTimestampType.MILLI_SECOND.value)
         tdSql.execute('reset query cache')
 
@@ -111,6 +112,9 @@ class TDTestCase:
         tdSql.query('describe `!@#$.%^&*()`')
         tdSql.checkRows(8)
 
+        tdSql.query('describe `stable`')
+        tdSql.checkRows(8)
+
         tdSql.query('select * from `3456`')
         tdSql.checkRows(1)
 
@@ -125,6 +129,9 @@ class TDTestCase:
 
         tdSql.query('select * from `none`')
         tdSql.checkRows(1)
+
+        tdSql.query('select * from `create`')
+        tdSql.checkRows(1)
     def stop(self):
         tdSql.close()
         tdLog.success("%s successfully executed" % __file__)