diff --git a/src/kit/shell/src/shellEngine.c b/src/kit/shell/src/shellEngine.c
index 7705db4b27e252a01933950fd309bd7ca179a008..a668524352d48af394268cb1a2cce41f43730a32 100644
--- a/src/kit/shell/src/shellEngine.c
+++ b/src/kit/shell/src/shellEngine.c
@@ -276,6 +276,8 @@ void shellRunCommandOnServer(TAOS *con, char command[]) {
   st = taosGetTimestampUs();
 
   TAOS_RES* pSql = taos_query(con, command);
+  result = pSql;  // set it into the global variable
+
   if (taos_errno(pSql)) {
     taos_error(pSql);
     return;
@@ -284,7 +286,8 @@ void shellRunCommandOnServer(TAOS *con, char command[]) {
   if (regex_match(command, "^\\s*use\\s+[a-zA-Z0-9_]+\\s*;\\s*$", REG_EXTENDED | REG_ICASE)) {
     fprintf(stdout, "Database changed.\n\n");
     fflush(stdout);
-    
+
+    result = NULL;
     taos_free_result(pSql);
     return;
   }
@@ -294,6 +297,7 @@ void shellRunCommandOnServer(TAOS *con, char command[]) {
     int error_no = 0;
     int numOfRows = shellDumpResult(pSql, fname, &error_no, printMode);
     if (numOfRows < 0) {
+      result = NULL;
       taos_free_result(pSql);
       return;
     }
@@ -315,7 +319,8 @@ void shellRunCommandOnServer(TAOS *con, char command[]) {
   if (fname != NULL) {
     wordfree(&full_path);
   }
-  
+
+  result = NULL;
   taos_free_result(pSql);
 }
 
@@ -419,8 +424,8 @@ static void dumpFieldToFile(FILE* fp, const char* val, TAOS_FIELD* field, int32_
   }
 }
 
-static int dumpResultToFile(const char* fname, TAOS_RES* result) {
-  TAOS_ROW row = taos_fetch_row(result);
+static int dumpResultToFile(const char* fname, TAOS_RES* tres) {
+  TAOS_ROW row = taos_fetch_row(tres);
   if (row == NULL) {
     return 0;
   }
@@ -441,9 +446,9 @@ static int dumpResultToFile(const char* fname, TAOS_RES* result) {
 
   wordfree(&full_path);
 
-  int num_fields = taos_num_fields(result);
-  TAOS_FIELD *fields = taos_fetch_fields(result);
-  int precision = taos_result_precision(result);
+  int num_fields = taos_num_fields(tres);
+  TAOS_FIELD *fields = taos_fetch_fields(tres);
+  int precision = taos_result_precision(tres);
 
   for (int col = 0; col < num_fields; col++) {
     if (col > 0) {
@@ -455,7 +460,7 @@ static int dumpResultToFile(const char* fname, TAOS_RES* result) {
   
   int numOfRows = 0;
   do {
-    int32_t* length = taos_fetch_lengths(result);
+    int32_t* length = taos_fetch_lengths(tres);
     for (int i = 0; i < num_fields; i++) {
       if (i > 0) {
         fputc(',', fp);
@@ -465,10 +470,13 @@ static int dumpResultToFile(const char* fname, TAOS_RES* result) {
     fputc('\n', fp);
 
     numOfRows++;
-    row = taos_fetch_row(result);
+    row = taos_fetch_row(tres);
   } while( row != NULL);
 
+  result = NULL;
+  taos_free_result(tres);
   fclose(fp);
+
   return numOfRows;
 }
 
@@ -769,8 +777,7 @@ void write_history() {
 
 void taos_error(TAOS_RES *tres) {
   fprintf(stderr, "\nDB error: %s\n", taos_errstr(tres));
-
-  /* free local resouce: allocated memory/metric-meta refcnt */
+  result = NULL;
   taos_free_result(tres);
 }
 
@@ -845,9 +852,9 @@ void shellGetGrantInfo(void *con) {
 
   char sql[] = "show grants";
 
-  result = taos_query(con, sql);
+  TAOS_RES* tres = taos_query(con, sql);
 
-  int code = taos_errno(result);
+  int code = taos_errno(tres);
   if (code != TSDB_CODE_SUCCESS) {
     if (code == TSDB_CODE_COM_OPS_NOT_SUPPORT) {
       fprintf(stdout, "Server is Community Edition, version is %s\n\n", taos_get_server_info(con));
@@ -857,18 +864,18 @@ void shellGetGrantInfo(void *con) {
     return;
   }
 
-  int num_fields = taos_field_count(result);
+  int num_fields = taos_field_count(tres);
   if (num_fields == 0) {
     fprintf(stderr, "\nInvalid grant information.\n");
     exit(0);
   } else {
-    if (result == NULL) {
+    if (tres == NULL) {
       fprintf(stderr, "\nGrant information is null.\n");
       exit(0);
     }
 
-    TAOS_FIELD *fields = taos_fetch_fields(result);
-    TAOS_ROW row = taos_fetch_row(result);
+    TAOS_FIELD *fields = taos_fetch_fields(tres);
+    TAOS_ROW row = taos_fetch_row(tres);
     if (row == NULL) {
       fprintf(stderr, "\nFailed to get grant information from server. Abort.\n");
       exit(0);
@@ -888,8 +895,8 @@ void shellGetGrantInfo(void *con) {
       fprintf(stdout, "Server is Enterprise %s Edition, version is %s and will expire at %s.\n", serverVersion, taos_get_server_info(con), expiretime);
     }
 
-    taos_free_result(result);
     result = NULL;
+    taos_free_result(tres);
   }
 
   fprintf(stdout, "\n");
diff --git a/src/kit/shell/src/shellMain.c b/src/kit/shell/src/shellMain.c
index 92474bdd03f56e6b5b0e0bde17a94a10606ac8d4..8481f498dd395cd449192d625d307ae812acaa30 100644
--- a/src/kit/shell/src/shellMain.c
+++ b/src/kit/shell/src/shellMain.c
@@ -15,7 +15,6 @@
 
 #include "os.h"
 #include "shell.h"
-#include "tsclient.h"
 
 pthread_t pid;
 
@@ -23,14 +22,6 @@ pthread_t pid;
 void interruptHandler(int signum) {
 #ifdef LINUX
   taos_stop_query(result);
-  if (result != NULL) {
-    /*
-     * we need to free result in async model, in order to avoid free
-     * results while the master thread is waiting for server response.
-     */
-    tscQueueAsyncFreeResult(result);
-  }
-  
   result = NULL;
 #else
   printf("\nReceive ctrl+c or other signal, quit shell.\n");
diff --git a/src/kit/taosdump/taosdump.c b/src/kit/taosdump/taosdump.c
index ee792c51166b090dd8ea104120ae5fd105791948..6ae78f6f731a0059902f21ded3693655287b4390 100644
--- a/src/kit/taosdump/taosdump.c
+++ b/src/kit/taosdump/taosdump.c
@@ -293,7 +293,6 @@ static error_t parse_opt(int key, char *arg, struct argp_state *state) {
 static struct argp argp = {options, parse_opt, args_doc, doc};
 
 TAOS *taos = NULL;
-TAOS_RES *result = NULL;
 char *command = NULL;
 char *lcommand = NULL;
 char *buffer = NULL;
@@ -463,10 +462,10 @@ int taosDumpOut(SDumpArguments *arguments) {
   taosDumpCharset(fp);
 
   sprintf(command, "show databases");
-  result = taos_query(taos, command);
+  TAOS_RES* result = taos_query(taos, command);
   int32_t code = taos_errno(result);
   if (code != 0) {
-    fprintf(stderr, "failed to run command: %s, reason: %s\n", command, taos_errstr(taos));
+    fprintf(stderr, "failed to run command: %s, reason: %s\n", command, taos_errstr(result));
     taos_free_result(result);
     goto _exit_failure;
   }
@@ -613,7 +612,7 @@ int taosDumpDb(SDbInfo *dbInfo, SDumpArguments *arguments, FILE *fp) {
   fprintf(fp, "USE %s\n\n", dbInfo->name);
 
   sprintf(command, "show tables");
-  result = taos_query(taos,command);
+  TAOS_RES* result = taos_query(taos,command);
   int32_t code = taos_errno(result);
   if (code != 0) {
     fprintf(stderr, "failed to run command %s, error: %s\n", command, taos_errstr(result));
@@ -717,7 +716,7 @@ void taosDumpCreateMTableClause(STableDef *tableDes, char *metric, int numOfCols
 
     sprintf(command, "select %s from %s limit 1", tableDes->cols[counter].field, tableDes->name);
 
-    result = taos_query(taos, command);
+    TAOS_RES* result = taos_query(taos, command);
     int32_t code = taos_errno(result);
     if (code != 0) {
       fprintf(stderr, "failed to run command %s, error: %s\n", command, taos_errstr(result));
@@ -795,7 +794,7 @@ int taosGetTableDes(char *table, STableDef *tableDes) {
 
   sprintf(command, "describe %s", table);
 
-  result = taos_query(taos, command);
+  TAOS_RES* result = taos_query(taos, command);
   int32_t code = taos_errno(result);
   if (code != 0) {
     fprintf(stderr, "failed to run command %s, error: %s\n", command, taos_errstr(result));
@@ -875,7 +874,7 @@ int32_t taosDumpMetric(char *metric, SDumpArguments *arguments, FILE *fp) {
   tstrncpy(tableRecord.metric, metric, TSDB_TABLE_NAME_LEN);
 
   sprintf(command, "select tbname from %s", metric);
-  result = taos_query(taos, command);
+  TAOS_RES* result = taos_query(taos, command);
   int32_t code = taos_errno(result);
   if (code != 0) {
     fprintf(stderr, "failed to run command %s, error: %s\n", command, taos_errstr(result));
@@ -928,7 +927,7 @@ int taosDumpTableData(FILE *fp, char *tbname, SDumpArguments *arguments) {
   sprintf(command, "select * from %s where _c0 >= %" PRId64 " and _c0 <= %" PRId64 " order by _c0 asc", tbname, arguments->start_time,
           arguments->end_time);
           
-  result = taos_query(taos, command);
+  TAOS_RES* result = taos_query(taos, command);
   int32_t code = taos_errno(result);
   if (code != 0) {
     fprintf(stderr, "failed to run command %s, reason: %s\n", command, taos_errstr(result));
@@ -1177,9 +1176,13 @@ int taosDumpIn(SDumpArguments *arguments) {
           tcommand = command;
         }
         taosReplaceCtrlChar(tcommand);
-        if (taos_query(taos, tcommand) == NULL)
+
+        TAOS_RES* result = taos_query(taos, tcommand);
+        if (taos_errno(result) != 0){
           fprintf(stderr, "linenu: %" PRId64 " failed to run command %s reason:%s \ncontinue...\n", linenu, command,
-                  taos_errstr(taos));
+                  taos_errstr(result));
+          taos_free_result(result);
+        }
 
         pstr = command;
         pstr[0] = '\0';
@@ -1225,12 +1228,12 @@ int taosDumpIn(SDumpArguments *arguments) {
         tcommand = command;
       }
       taosReplaceCtrlChar(tcommand);
-      result = taos_query(taos, tcommand);
+      TAOS_RES* result = taos_query(taos, tcommand);
       int32_t code = taos_errno(result);
       if (code != 0) 
       {
         fprintf(stderr, "linenu:%" PRId64 " failed to run command %s reason: %s \ncontinue...\n", linenu, command,
-                taos_errstr(taos));
+                taos_errstr(result));
       }
       taos_free_result(result);
     }