diff --git a/source/dnode/vnode/src/meta/metaTable.c b/source/dnode/vnode/src/meta/metaTable.c
index ce2a1c4b89336dcd48ae481960e614978f532030..932afe89371433d16b162d9fc52a3c74fb2b0561 100644
--- a/source/dnode/vnode/src/meta/metaTable.c
+++ b/source/dnode/vnode/src/meta/metaTable.c
@@ -362,8 +362,9 @@ int metaAlterSTable(SMeta *pMeta, int64_t version, SVCreateStbReq *pReq) {
   // update uid index
   metaUpdateUidIdx(pMeta, &nStbEntry);
 
-  if (oStbEntry.pBuf) taosMemoryFree(oStbEntry.pBuf);
   metaULock(pMeta);
+
+  if (oStbEntry.pBuf) taosMemoryFree(oStbEntry.pBuf);
   tDecoderClear(&dc);
   tdbTbcClose(pTbDbc);
   tdbTbcClose(pUidIdxc);
@@ -922,6 +923,8 @@ static int metaUpdateTableTagVal(SMeta *pMeta, int64_t version, SVAlterTbReq *pA
     taosArrayDestroy(pTagArray);
   }
 
+  metaWLock(pMeta);
+
   // save to table.db
   metaSaveToTbDb(pMeta, &ctbEntry);
 
@@ -936,6 +939,8 @@ static int metaUpdateTableTagVal(SMeta *pMeta, int64_t version, SVAlterTbReq *pA
   tdbTbUpsert(pMeta->pCtbIdx, &ctbIdxKey, sizeof(ctbIdxKey), ctbEntry.ctbEntry.pTags,
               ((STag *)(ctbEntry.ctbEntry.pTags))->len, &pMeta->txn);
 
+  metaULock(pMeta);
+
   tDecoderClear(&dc1);
   tDecoderClear(&dc2);
   if (ctbEntry.ctbEntry.pTags) taosMemoryFree((void *)ctbEntry.ctbEntry.pTags);