diff --git a/source/common/src/tdataformat.c b/source/common/src/tdataformat.c
index eba30ff506c9ef2d55f4917380717c2ea48084f8..0bb283708dbeba41c33fb3fda749394bad42dfaa 100644
--- a/source/common/src/tdataformat.c
+++ b/source/common/src/tdataformat.c
@@ -2061,8 +2061,8 @@ int32_t tColDataCopy(SColData *pColDataFrom, SColData *pColData, xMallocFn xMall
   }
 
   // value
-  if (pColData->nVal) {
-    pColData->pData = xMalloc(arg, pColData->nVal);
+  if (pColData->nData) {
+    pColData->pData = xMalloc(arg, pColData->nData);
     if (pColData->pData == NULL) {
       code = TSDB_CODE_OUT_OF_MEMORY;
       goto _exit;