diff --git a/src/client/src/tscFunctionImpl.c b/src/client/src/tscFunctionImpl.c
index be3dce9c0e8efb0608d4c5a50f8a091987ef1326..2d913b2f20064be0a358d0419bf221b4e8e54f92 100644
--- a/src/client/src/tscFunctionImpl.c
+++ b/src/client/src/tscFunctionImpl.c
@@ -1043,10 +1043,10 @@ static bool max_func_setup(SQLFunctionCtx *pCtx) {
       *((int32_t *)pCtx->aOutputBuf) = INT32_MIN;
       break;
     case TSDB_DATA_TYPE_FLOAT:
-      *((float *)pCtx->aOutputBuf) = -FLT_MIN;
+      *((float *)pCtx->aOutputBuf) = -FLT_MAX;
       break;
     case TSDB_DATA_TYPE_DOUBLE:
-      *((double *)pCtx->aOutputBuf) = -DBL_MIN;
+      *((double *)pCtx->aOutputBuf) = -DBL_MAX;
       break;
     case TSDB_DATA_TYPE_BIGINT:
       *((int64_t *)pCtx->aOutputBuf) = INT64_MIN;