diff --git a/src/query/inc/qScript.h b/src/query/inc/qScript.h
index d43413e2e528fdd6567dee14d607efcc4eb93814..574bb51368afeaeddef5fbd5c5bd8469fbe0cdef 100644
--- a/src/query/inc/qScript.h
+++ b/src/query/inc/qScript.h
@@ -60,8 +60,9 @@ typedef struct ScriptCtx {
 
 int taosLoadScriptInit(void *pInit);
 void taosLoadScriptNormal(void *pInit, char *pInput, int16_t iType, int16_t iBytes, int32_t numOfRows, 
-    int64_t *ptsList, char* pOutput, char *ptsOutput, int32_t *numOfOutput, int16_t oType, int16_t oBytes);
-void taosLoadScriptFinalize(void *pInit, char *pOutput, int32_t *output);
+    int64_t *ptsList, int64_t key, char* pOutput, char *ptsOutput, int32_t *numOfOutput, int16_t oType, int16_t oBytes);
+void taosLoadScriptFinalize(void *pInit, int64_t key, char *pOutput, int32_t *output);
+void taosLoadScriptMerge(void *pCtx, char* data, int32_t numOfRows, char* dataOutput, int32_t* numOfOutput);
 void taosLoadScriptDestroy(void *pInit);
 
 typedef struct {
diff --git a/src/query/inc/qUdf.h b/src/query/inc/qUdf.h
index 26573cb743f1897da21928ddbd80b0e151b1b122..1083b1e698f7591aae4586c7722e5343cd9c4d86 100644
--- a/src/query/inc/qUdf.h
+++ b/src/query/inc/qUdf.h
@@ -57,8 +57,8 @@ typedef struct SUdfInfo {
 
 typedef int32_t (*scriptInitFunc)(void *pCtx);
 typedef void (*scriptNormalFunc)(void *pCtx, char* data, int16_t iType, int16_t iBytes, int32_t numOfRows,
-                                 int64_t* ts, char* dataOutput, char* tsOutput, int32_t* numOfOutput, int16_t oType, int16_t oBytes);
-typedef void (*scriptFinalizeFunc)(void *pCtx, char* dataOutput, int32_t* numOfOutput);
+                                 int64_t* ptList, int64_t key, char* dataOutput, char* tsOutput, int32_t* numOfOutput, int16_t oType, int16_t oBytes);
+typedef void (*scriptFinalizeFunc)(void *pCtx, int64_t key, char* dataOutput, int32_t* numOfOutput);
 typedef void (*scriptMergeFunc)(void *pCtx, char* data, int32_t numOfRows, char* dataOutput, int32_t* numOfOutput);
 typedef void (*scriptDestroyFunc)(void* pCtx);
 
diff --git a/src/query/src/qExecutor.c b/src/query/src/qExecutor.c
index 3e405c6c924a062a8cd0c5571aabaa4ee4befca1..64f55a1d9989ca51801387ac746f66494b9af879 100644
--- a/src/query/src/qExecutor.c
+++ b/src/query/src/qExecutor.c
@@ -715,7 +715,7 @@ void doInvokeUdf(SUdfInfo* pUdfInfo, SQLFunctionCtx *pCtx, int32_t idx, int32_t
     case TSDB_UDF_FUNC_NORMAL:
       if (pUdfInfo->isScript) {
         (*(scriptNormalFunc)pUdfInfo->funcs[TSDB_UDF_FUNC_NORMAL])(pUdfInfo->pScriptCtx,
-                     (char *)pCtx->pInput + idx * pCtx->inputType, pCtx->inputType, pCtx->inputBytes, pCtx->size, pCtx->ptsList, pCtx->pOutput,
+                     (char *)pCtx->pInput + idx * pCtx->inputType, pCtx->inputType, pCtx->inputBytes, pCtx->size, pCtx->ptsList, pCtx->startTs, pCtx->pOutput,
                     (char *)pCtx->ptsOutputBuf, &output, pCtx->outputType, pCtx->outputBytes);
       } else {
         SResultRowCellInfo *pResInfo = GET_RES_INFO(pCtx);
@@ -739,7 +739,11 @@ void doInvokeUdf(SUdfInfo* pUdfInfo, SQLFunctionCtx *pCtx, int32_t idx, int32_t
       break;
 
     case TSDB_UDF_FUNC_MERGE:
-      (*(udfMergeFunc)pUdfInfo->funcs[TSDB_UDF_FUNC_MERGE])(pCtx->pInput, pCtx->size, pCtx->pOutput, &output, &pUdfInfo->init);
+      if (pUdfInfo->isScript) {
+        (*(scriptMergeFunc)pUdfInfo->funcs[TSDB_UDF_FUNC_MERGE])(pUdfInfo->pScriptCtx, pCtx->pInput, pCtx->size, pCtx->pOutput, &output);
+      } else {
+        (*(udfMergeFunc)pUdfInfo->funcs[TSDB_UDF_FUNC_MERGE])(pCtx->pInput, pCtx->size, pCtx->pOutput, &output, &pUdfInfo->init);
+      }
       
       // set the output value exist
       pCtx->resultInfo->numOfRes = output;
@@ -753,7 +757,7 @@ void doInvokeUdf(SUdfInfo* pUdfInfo, SQLFunctionCtx *pCtx, int32_t idx, int32_t
       SResultRowCellInfo *pResInfo = GET_RES_INFO(pCtx);
       void *interBuf = (void *)GET_ROWCELL_INTERBUF(pResInfo);
       if (pUdfInfo->isScript) {
-        (*(scriptFinalizeFunc)pUdfInfo->funcs[TSDB_UDF_FUNC_FINALIZE])(pUdfInfo->pScriptCtx, pCtx->pOutput, &output);
+        (*(scriptFinalizeFunc)pUdfInfo->funcs[TSDB_UDF_FUNC_FINALIZE])(pUdfInfo->pScriptCtx, pCtx->startTs, pCtx->pOutput, &output);
       } else {    
         (*(udfFinalizeFunc)pUdfInfo->funcs[TSDB_UDF_FUNC_FINALIZE])(pCtx->pOutput, interBuf, &output, &pUdfInfo->init);
       }
@@ -3279,6 +3283,7 @@ void finalizeQueryResult(SOperatorInfo* pOperator, SQLFunctionCtx* pCtx, SResult
       setResultOutputBuf(pRuntimeEnv, buf, pCtx, numOfOutput, rowCellInfoOffset);
 
       for (int32_t j = 0; j < numOfOutput; ++j) {
+        pCtx[j].startTs  = buf->win.skey;
         if (pCtx[j].functionId < 0) {
           doInvokeUdf(pRuntimeEnv->pUdfInfo, &pCtx[j], 0, TSDB_UDF_FUNC_FINALIZE);
         } else {
@@ -6676,6 +6681,7 @@ int32_t initUdfInfo(SUdfInfo* pUdfInfo) {
 
     if (pUdfInfo->funcType == TSDB_UDF_TYPE_AGGREGATE) {
       pUdfInfo->funcs[TSDB_UDF_FUNC_FINALIZE] =  taosLoadScriptFinalize;
+      pUdfInfo->funcs[TSDB_UDF_FUNC_MERGE]    =  taosLoadScriptMerge;
     }
     pUdfInfo->funcs[TSDB_UDF_FUNC_DESTROY] = taosLoadScriptDestroy;
 
diff --git a/src/query/src/qScript.c b/src/query/src/qScript.c
index 3319428930b9bd5c252892e40a7562688b2bf2c0..d106c5f444c5cdd8e3a63b0c7855cb64f8d38150 100644
--- a/src/query/src/qScript.c
+++ b/src/query/src/qScript.c
@@ -103,7 +103,7 @@ int taosLoadScriptInit(void* pInit) {
   return 0;
 }
 void taosLoadScriptNormal(void *pInit, char *pInput, int16_t iType, int16_t iBytes, int32_t numOfRows, 
-    int64_t *ptsList, char* pOutput, char *ptsOutput, int32_t *numOfOutput, int16_t oType, int16_t oBytes) { 
+    int64_t *ptsList, int64_t key, char* pOutput, char *ptsOutput, int32_t *numOfOutput, int16_t oType, int16_t oBytes) { 
   ScriptCtx* pCtx = pInit;
   char funcName[MAX_FUNC_NAME] = {0};
   sprintf(funcName, "%s_add", pCtx->funcName);
@@ -124,8 +124,9 @@ void taosLoadScriptNormal(void *pInit, char *pInput, int16_t iType, int16_t iByt
   if (lua_istable(lua, -1)) {
     isGlobalState = true; 
   }
+  lua_pushnumber(lua, key);
   // do call lua script 
-  if (lua_pcall(lua, 2, 1, 0) != 0) {
+  if (lua_pcall(lua, 3, 1, 0) != 0) {
     qError("SCRIPT ERROR: %s", lua_tostring(lua, -1)); 
     lua_pop(lua, -1);
     return;
@@ -139,22 +140,51 @@ void taosLoadScriptNormal(void *pInit, char *pInput, int16_t iType, int16_t iByt
   *numOfOutput = tNumOfOutput;
 }
 
+void taosLoadScriptMerge(void *pInit, char* data, int32_t numOfRows, char* pOutput, int32_t* numOfOutput) {
+  ScriptCtx *pCtx = pInit;
+  char funcName[MAX_FUNC_NAME] = {0};
+  sprintf(funcName, "%s_merge", pCtx->funcName);
+
+  lua_State* lua  = pCtx->pEnv->lua_state;   
+  lua_getglobal(lua, funcName);
+  if (!lua_isfunction(lua, -1)) {
+    qError("SCRIPT ERROR: %s", lua_tostring(lua, -1)); 
+    return;
+  }
+
+  lua_getglobal(lua, "global"); 
+  if (lua_pcall(lua, 1, 1, 0) != 0) {
+    qError("SCRIPT ERROR: %s", lua_tostring(lua, -1)); 
+    lua_pop(lua, -1);
+    return;
+  }
+  int tNumOfOutput = 0; 
+  luaValueToTaosType(lua, pOutput, &tNumOfOutput, pCtx->resType, pCtx->resBytes);
+  *numOfOutput = tNumOfOutput;
+}
+
 //do not support agg now
-void taosLoadScriptFinalize(void *pInit, char *pOutput, int32_t* numOfOutput) {
+void taosLoadScriptFinalize(void *pInit,int64_t key, char *pOutput, int32_t* numOfOutput) {
   ScriptCtx *pCtx = pInit;
   char funcName[MAX_FUNC_NAME] = {0};
   sprintf(funcName, "%s_finalize", pCtx->funcName);
   
   lua_State* lua  = pCtx->pEnv->lua_state;   
   lua_getglobal(lua, funcName);
+  if (!lua_isfunction(lua, -1)) {
+    qError("SCRIPT ERROR: %s", lua_tostring(lua, -1)); 
+    return;
+  }
 
   lua_getglobal(lua, "global"); 
 
-  if (lua_pcall(lua, 1, 1, 0) != 0) {
+  lua_pushnumber(lua, key);
+  if (lua_pcall(lua, 2, 2, 0) != 0) {
     qError("SCRIPT ERROR: %s", lua_tostring(lua, -1)); 
     lua_pop(lua, -1);
     return;
   }
+  lua_setglobal(lua, "global"); 
   int tNumOfOutput = 0; 
   luaValueToTaosType(lua, pOutput, &tNumOfOutput, pCtx->resType, pCtx->resBytes);
   *numOfOutput = tNumOfOutput;
@@ -256,6 +286,8 @@ void luaValueToTaosType(lua_State *lua, char *interBuf, int32_t *numOfOutput, in
       }
       break;
     default:
+      setNull(interBuf, oType, oBytes);
+      sz = 1;
       break; 
   }
   lua_pop(lua,1); // pop ret value from script  
diff --git a/tests/script/sh/demo.lua b/tests/script/sh/demo.lua
index a79015bb87712b71b00eb48e02f4b7e25e07ae32..2bb660b6b3d9b256921aa757c8565dde4526a9dd 100644
--- a/tests/script/sh/demo.lua
+++ b/tests/script/sh/demo.lua
@@ -1,21 +1,43 @@
 funcName = "test"
 
 global =  {} 
-global["sum"] = 0.0
-global["num"] = 0
 
 function test_init()
   return global  
 end
 
-function test_add(rows, ans)
+function test_add(rows, ans, key)
+  t = {}
+  t["sum"] = 0.0
+  t["num"] = 0
   for i=1, #rows do
-    ans["sum"] = ans["sum"] + rows[i] * rows[i]  
+    t["sum"] = t["sum"] + rows[i] * rows[i]  
   end
-  ans["num"] = ans["num"] + #rows  
+  t["num"] = #rows  
+
+
+  if (ans[key] ~= nil)    
+  then
+    ans[key]["sum"] = ans[key]["sum"] + t["sum"]
+    ans[key]["num"] = ans[key]["num"] + t["num"]
+  else 
+    ans[key] = t
+  end
+  
   return ans; 
 end
 
-function test_finalize(ans) 
-  return ans["sum"]/ans["num"]; 
+function test_finalize(ans, key) 
+  local ret = 0.0 
+
+  if (ans[key] ~= nil)    
+  then
+    ret = ans[key]["sum"]/ans[key]["num"]
+    ans[key]["sum"] = 0.0 
+    ans[key]["num"] = 0
+  else 
+    ret = inf 
+  end
+  
+  return ret, ans
 end