diff --git a/src/client/src/tscSQLParser.c b/src/client/src/tscSQLParser.c
index 9f557f5529e03ee504aea2c30cc6bfac113a06aa..d90a19da279170c89c180d46f2ed69828d788678 100644
--- a/src/client/src/tscSQLParser.c
+++ b/src/client/src/tscSQLParser.c
@@ -4452,6 +4452,7 @@ int32_t setAlterTableInfo(SSqlObj* pSql, struct SSqlInfo* pInfo) {
     
     tVariantList* pVarList = pAlterSQL->varList;
     tVariant*     pTagName = &pVarList->a[0].pVar;
+    int16_t       numOfTags = tscGetNumOfTags(pTableMeta);
 
     SColumnIndex columnIndex = COLUMN_INDEX_INITIALIZER;
     SSQLToken    name = {.type = TK_STRING, .z = pTagName->pz, .n = pTagName->nLen};
@@ -4475,8 +4476,10 @@ int32_t setAlterTableInfo(SSqlObj* pSql, struct SSqlInfo* pInfo) {
         (pVarList->a[1].pVar.nLen + VARSTR_HEADER_SIZE) > pTagsSchema->bytes) {
       return invalidSqlErrMsg(pQueryInfo->msg, msg14);
     }
-  
-    int32_t size = sizeof(SUpdateTableTagValMsg) + pTagsSchema->bytes + TSDB_EXTRA_PAYLOAD_SIZE;
+
+    int32_t schemaLen = sizeof(STColumn) * numOfTags;
+    int32_t size = sizeof(SUpdateTableTagValMsg) + pTagsSchema->bytes + schemaLen + TSDB_EXTRA_PAYLOAD_SIZE;
+
     if (TSDB_CODE_SUCCESS != tscAllocPayload(pCmd, size)) {
       tscError("%p failed to malloc for alter table msg", pSql);
       return TSDB_CODE_TSC_OUT_OF_MEMORY;
@@ -4487,11 +4490,25 @@ int32_t setAlterTableInfo(SSqlObj* pSql, struct SSqlInfo* pInfo) {
     pUpdateMsg->tid = htonl(pTableMeta->sid);
     pUpdateMsg->uid = htobe64(pTableMeta->uid);
     pUpdateMsg->colId = htons(pTagsSchema->colId);
-    pUpdateMsg->type  = htons(pTagsSchema->type);
-    pUpdateMsg->bytes = htons(pTagsSchema->bytes);
     pUpdateMsg->tversion = htons(pTableMeta->tversion);
-    
-    tVariantDump(&pVarList->a[1].pVar, pUpdateMsg->data, pTagsSchema->type, true);
+    pUpdateMsg->numOfTags = htons(numOfTags);
+    pUpdateMsg->schemaLen = htonl(schemaLen);
+
+    // the schema is located after the msg body, then followed by true tag value
+    char* d = pUpdateMsg->data;
+    SSchema* pTagCols = tscGetTableTagSchema(pTableMeta);
+    for (int i = 0; i < numOfTags; ++i) {
+      STColumn* pCol = (STColumn*) d;
+      pCol->colId = htons(pTagCols[i].colId);
+      pCol->bytes = htons(pTagCols[i].bytes);
+      pCol->type  = pTagCols[i].type;
+      pCol->offset = 0;
+
+      d += sizeof(STColumn);
+    }
+
+    // copy the tag value to msg body
+    tVariantDump(&pVarList->a[1].pVar, pUpdateMsg->data + schemaLen, pTagsSchema->type, true);
     
     int32_t len = 0;
     if (pTagsSchema->type != TSDB_DATA_TYPE_BINARY && pTagsSchema->type != TSDB_DATA_TYPE_NCHAR) {
@@ -4502,7 +4519,7 @@ int32_t setAlterTableInfo(SSqlObj* pSql, struct SSqlInfo* pInfo) {
     
     pUpdateMsg->tagValLen = htonl(len);  // length may be changed after dump data
     
-    int32_t total = sizeof(SUpdateTableTagValMsg) + len;
+    int32_t total = sizeof(SUpdateTableTagValMsg) + len + schemaLen;
     pUpdateMsg->head.contLen = htonl(total);
     
   } else if (pAlterSQL->type == TSDB_ALTER_TABLE_ADD_COLUMN) {
diff --git a/src/inc/taosmsg.h b/src/inc/taosmsg.h
index cb25242d27d3f8e50af643df3c447c7aaae76484..6155f08e76646ff887a51be60a0bfa500a6f873c 100644
--- a/src/inc/taosmsg.h
+++ b/src/inc/taosmsg.h
@@ -285,9 +285,9 @@ typedef struct {
   int32_t   tid;
   int16_t   tversion;
   int16_t   colId;
-  int16_t   type;
-  int16_t   bytes;
   int32_t   tagValLen;
+  int16_t   numOfTags;
+  int32_t   schemaLen;
   char      data[];
 } SUpdateTableTagValMsg;
 
diff --git a/src/tsdb/src/tsdbMeta.c b/src/tsdb/src/tsdbMeta.c
index dafc7dbb1bcb2eab6fa5f8f6587cc322879512d1..4d66f12178dd87b1dd870537e3fd5e64d73f19e3 100644
--- a/src/tsdb/src/tsdbMeta.c
+++ b/src/tsdb/src/tsdbMeta.c
@@ -310,7 +310,9 @@ int tsdbUpdateTagValue(TSDB_REPO_T *repo, SUpdateTableTagValMsg *pMsg) {
     tsdbRemoveTableFromIndex(pMeta, pTable);
   }
   // TODO: remove table from index if it is the first column of tag
-  tdSetKVRowDataOfCol(&pTable->tagVal, htons(pMsg->colId), htons(pMsg->type), pMsg->data);
+  // TODO: convert the tag schema from client, and then extract the type and bytes from schema according to colId
+
+//  tdSetKVRowDataOfCol(&pTable->tagVal, htons(pMsg->colId), htons(pMsg->type), pMsg->data);
   if (schemaColAt(pTagSchema, DEFAULT_TAG_INDEX_COLUMN)->colId == htons(pMsg->colId)) {
     tsdbAddTableIntoIndex(pMeta, pTable);
   }