diff --git a/src/kit/taosdemo/taosdemo.c b/src/kit/taosdemo/taosdemo.c
index 60785ec004776aa39ab719de5ca0975922b70d10..53e7d2398450fe22a11da1e7254e0c2ab5f02ea4 100644
--- a/src/kit/taosdemo/taosdemo.c
+++ b/src/kit/taosdemo/taosdemo.c
@@ -881,6 +881,7 @@ int main(int argc, char *argv[]) {
     taos_close(rInfo->taos);
   }
 
+  taos_cleanup();
   return 0;
 }
 
diff --git a/tests/examples/c/asyncdemo.c b/tests/examples/c/asyncdemo.c
index 225c4f7541ec7cd7fb4784b8de94d8b47c4e3e36..c6cc89b31d6280c45ea30b33509eed5ebdf0dc08 100644
--- a/tests/examples/c/asyncdemo.c
+++ b/tests/examples/c/asyncdemo.c
@@ -68,6 +68,7 @@ static void queryDB(TAOS *taos, char *command) {
     fprintf(stderr, "Failed to run %s, reason: %s\n", command, taos_errstr(pSql));
     taos_free_result(pSql);
     taos_close(taos);
+    taos_cleanup();
     exit(EXIT_FAILURE);
   }
 
@@ -176,6 +177,7 @@ void taos_error(TAOS *con)
 {
   fprintf(stderr, "TDengine error: %s\n", taos_errstr(con));
   taos_close(con);
+  taos_cleanup();
   exit(1);
 }
 
@@ -211,6 +213,8 @@ void taos_insert_call_back(void *param, TAOS_RES *tres, int code)
       printf("%lld mseconds to insert %d data points\n", (et - st) / 1000, points*numOfTables);
     }
   }
+  
+  taos_free_result(tres);
 }
 
 void taos_retrieve_call_back(void *param, TAOS_RES *tres, int numOfRows)
@@ -222,7 +226,7 @@ void taos_retrieve_call_back(void *param, TAOS_RES *tres, int numOfRows)
 
     for (int i = 0; i<numOfRows; ++i) {
       // synchronous API to retrieve a row from batch of records
-      /*TAOS_ROW row = */taos_fetch_row(tres);
+      /*TAOS_ROW row = */(void)taos_fetch_row(tres);
       // process row
     }
 
@@ -236,7 +240,7 @@ void taos_retrieve_call_back(void *param, TAOS_RES *tres, int numOfRows)
     if (numOfRows < 0)
       printf("%s retrieve failed, code:%d\n", pTable->name, numOfRows);
 
-    taos_free_result(tres);
+    //taos_free_result(tres);
     printf("%d rows data retrieved from %s\n", pTable->rowsRetrieved, pTable->name);
 
     tablesProcessed++;
@@ -246,6 +250,8 @@ void taos_retrieve_call_back(void *param, TAOS_RES *tres, int numOfRows)
       printf("%lld mseconds to query %d data rows\n", (et - st) / 1000, points * numOfTables);
     }
   }
+
+  taos_free_result(tres);
 }
 
 void taos_select_call_back(void *param, TAOS_RES *tres, int code)
@@ -261,6 +267,10 @@ void taos_select_call_back(void *param, TAOS_RES *tres, int code)
   }
   else {
     printf("%s select failed, code:%d\n", pTable->name, code);
+    taos_free_result(tres);
+    taos_cleanup();
     exit(1);
   }
+
+  taos_free_result(tres);
 }