diff --git a/test/src/main/java/org/apache/rocketmq/test/client/rmq/RMQAsyncSendProducer.java b/test/src/main/java/org/apache/rocketmq/test/client/rmq/RMQAsyncSendProducer.java
index 4a2ce2b7ad975a50d204b5ab4afd3719a4e13d46..2f8af68b31eff537190c25825c8a0f81bae0aa5d 100644
--- a/test/src/main/java/org/apache/rocketmq/test/client/rmq/RMQAsyncSendProducer.java
+++ b/test/src/main/java/org/apache/rocketmq/test/client/rmq/RMQAsyncSendProducer.java
@@ -18,6 +18,7 @@
 package org.apache.rocketmq.test.client.rmq;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicInteger;
 import org.apache.log4j.Logger;
@@ -38,7 +39,8 @@ public class RMQAsyncSendProducer extends AbstractMQProducer {
     private String nsAddr = null;
     private DefaultMQProducer producer = null;
     private SendCallback sendCallback = null;
-    private List<org.apache.rocketmq.client.producer.SendResult> successSendResult = new ArrayList<org.apache.rocketmq.client.producer.SendResult>();
+    private List<org.apache.rocketmq.client.producer.SendResult> successSendResult = Collections
+        .synchronizedList(new ArrayList<org.apache.rocketmq.client.producer.SendResult>());
     private AtomicInteger exceptionMsgCount = new AtomicInteger(
         0);
     private int msgSize = 0;
diff --git a/test/src/test/java/org/apache/rocketmq/test/client/producer/async/AsyncSendWithMessageQueueIT.java b/test/src/test/java/org/apache/rocketmq/test/client/producer/async/AsyncSendWithMessageQueueIT.java
index 3efc5317752fc509798e96a3a35356c78c85820d..2147285414c60eed7a98a3f6e2bbaa7788c8166e 100644
--- a/test/src/test/java/org/apache/rocketmq/test/client/producer/async/AsyncSendWithMessageQueueIT.java
+++ b/test/src/test/java/org/apache/rocketmq/test/client/producer/async/AsyncSendWithMessageQueueIT.java
@@ -68,7 +68,7 @@ public class AsyncSendWithMessageQueueIT extends BaseConf {
 
         producer.clearMsg();
         consumer.clearMsg();
-
+	producer.getSuccessSendResult().clear();
         mq = new MessageQueue(topic, broker2Name, queueId);
         producer.asyncSend(msgSize, mq);
         producer.waitForResponse(10 * 1000);