diff --git a/src/client/src/tscUtil.c b/src/client/src/tscUtil.c
index 7af6a080ed0b1c9f4edd46bf6631f0c53c76554a..7064f3981dfec4c8366ef8855d0be4b5baeda3a1 100644
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@@ -4192,9 +4192,19 @@ static void tscSubqueryCompleteCallback(void* param, TAOS_RES* tres, int code) {
 
 int32_t doInitSubState(SSqlObj* pSql, int32_t numOfSubqueries) {
   //bug fix. Above doInitSubState level, the loop invocation with the same SSqlObj will be fail.
-  //assert(pSql->subState.numOfSub == 0 && pSql->pSubs == NULL && pSql->subState.states == NULL);
+  //assert(pSql->subState.numOfSub == 0 && pSql->pSubs == NULL && pSql->subState.states == NULL);  
+  if(pSql->pSubs) {
+    free(pSql->pSubs);
+    pSql->pSubs = NULL;
+  }
+  
+  if(pSql->subState.states) {
+    free(pSql->subState.states);
+    pSql->subState.states = NULL;
+  }
+  
   pSql->subState.numOfSub = numOfSubqueries;
-
+  
   pSql->pSubs = calloc(pSql->subState.numOfSub, POINTER_BYTES);
   pSql->subState.states = calloc(pSql->subState.numOfSub, sizeof(int8_t));