diff --git a/src/main/java/com/tianyalei/async/group/WorkerWrapper.java b/src/main/java/com/tianyalei/async/group/WorkerWrapper.java
index 61a3e7f..404ab44 100755
--- a/src/main/java/com/tianyalei/async/group/WorkerWrapper.java
+++ b/src/main/java/com/tianyalei/async/group/WorkerWrapper.java
@@ -1,6 +1,5 @@
 package com.tianyalei.async.group;
 
-
 import com.tianyalei.async.callback.DefaultCallback;
 import com.tianyalei.async.callback.ICallback;
 import com.tianyalei.async.callback.IWorker;
@@ -56,7 +55,7 @@ public class WorkerWrapper<T, V> {
     /**
      * 也是个钩子变量，用来存临时的结果
      */
-    private volatile WorkResult<V> workResult;
+    private volatile WorkResult<V> workResult = WorkResult.defaultResult();
 
     private static final int FINISH = 1;
     private static final int ERROR = 2;
@@ -205,7 +204,7 @@ public class WorkerWrapper<T, V> {
             WorkerWrapper workerWrapper = dependWrapper.getDependWrapper();
             WorkResult tempWorkResult = workerWrapper.getWorkResult();
             //为null或者isWorking，说明它依赖的某个任务还没执行到或没执行完
-            if (tempWorkResult == null || workerWrapper.getState() == WORKING) {
+            if (workerWrapper.getState() == INIT || workerWrapper.getState() == WORKING) {
                 existNoFinish = true;
                 break;
             }
@@ -276,7 +275,8 @@ public class WorkerWrapper<T, V> {
             return false;
         }
 
-        if (workResult == null) {
+        //尚未处理过结果
+        if (checkIsNullResult()) {
             if (e == null) {
                 workResult = defaultResult();
             } else {
@@ -293,7 +293,7 @@ public class WorkerWrapper<T, V> {
      */
     private WorkResult<V> workerDoJob() {
         //避免重复执行
-        if (workResult != null) {
+        if (!checkIsNullResult()) {
             return workResult;
         }
         try {
@@ -307,20 +307,20 @@ public class WorkerWrapper<T, V> {
             //执行耗时操作
             V resultValue = worker.action(getParam());
 
-            WorkResult<V> tempResult = new WorkResult<>(resultValue, ResultState.SUCCESS);
-
             //如果状态不是在working,说明别的地方已经修改了
             if (!compareAndSetState(WORKING, FINISH)) {
                 return workResult;
             }
+
+            workResult.setResultState(ResultState.SUCCESS);
+            workResult.setResult(resultValue);
             //回调成功
-            callback.result(true, getParam(), tempResult);
-            workResult = tempResult;
+            callback.result(true, getParam(), workResult);
 
             return workResult;
         } catch (Exception e) {
             //避免重复回调
-            if (workResult != null) {
+            if (!checkIsNullResult()) {
                 return workResult;
             }
             fastFail(WORKING, e);
@@ -328,6 +328,10 @@ public class WorkerWrapper<T, V> {
         }
     }
 
+    private boolean checkIsNullResult() {
+        return ResultState.DEFAULT == workResult.getResultState();
+    }
+
 
     public WorkerWrapper addNext(WorkerWrapper<?, ?>... nextWrappers) {
         if (nextWrappers == null) {
@@ -385,11 +389,16 @@ public class WorkerWrapper<T, V> {
     }
 
     private WorkResult<V> defaultResult() {
-        return new WorkResult<>(getWorker().defaultValue(), ResultState.TIMEOUT);
+        workResult.setResultState(ResultState.TIMEOUT);
+        workResult.setResult(getWorker().defaultValue());
+        return workResult;
     }
 
     private WorkResult<V> defaultExResult(Exception ex) {
-        return new WorkResult<>(getWorker().defaultValue(), ResultState.EXCEPTION, ex);
+        workResult.setResultState(ResultState.EXCEPTION);
+        workResult.setResult(getWorker().defaultValue());
+        workResult.setEx(ex);
+        return workResult;
     }
 
     private WorkResult<V> getNoneNullWorkResult() {
diff --git a/src/main/java/com/tianyalei/async/worker/ResultState.java b/src/main/java/com/tianyalei/async/worker/ResultState.java
index 002dda1..c6208a2 100755
--- a/src/main/java/com/tianyalei/async/worker/ResultState.java
+++ b/src/main/java/com/tianyalei/async/worker/ResultState.java
@@ -7,5 +7,6 @@ package com.tianyalei.async.worker;
 public enum ResultState {
     SUCCESS,
     TIMEOUT,
-    EXCEPTION
+    EXCEPTION,
+    DEFAULT  //默认状态
 }
diff --git a/src/main/java/com/tianyalei/async/worker/WorkResult.java b/src/main/java/com/tianyalei/async/worker/WorkResult.java
index ca425e0..40d04f5 100755
--- a/src/main/java/com/tianyalei/async/worker/WorkResult.java
+++ b/src/main/java/com/tianyalei/async/worker/WorkResult.java
@@ -25,7 +25,7 @@ public class WorkResult<V> {
     }
 
     public static WorkResult defaultResult() {
-        return new WorkResult<>(null, ResultState.TIMEOUT);
+        return new WorkResult<>(null, ResultState.DEFAULT);
     }
 
     @Override
diff --git a/src/main/java/com/tianyalei/test/depend/ParWorker.java b/src/main/java/com/tianyalei/test/depend/ParWorker.java
new file mode 100755
index 0000000..6f2355a
--- /dev/null
+++ b/src/main/java/com/tianyalei/test/depend/ParWorker.java
@@ -0,0 +1,40 @@
+package com.tianyalei.test.depend;
+
+
+import com.tianyalei.async.callback.ICallback;
+import com.tianyalei.async.callback.IWorker;
+import com.tianyalei.async.executor.timer.SystemClock;
+import com.tianyalei.async.worker.WorkResult;
+
+/**
+ * @author wuweifeng wrote on 2019-11-20.
+ */
+public class ParWorker implements IWorker<String, User>, ICallback<String, User> {
+
+    @Override
+    public User action(String object) {
+        try {
+            Thread.sleep(1000);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+        return new User("user0");
+    }
+
+
+    @Override
+    public User defaultValue() {
+        return new User("default User");
+    }
+
+    @Override
+    public void begin() {
+        //System.out.println(Thread.currentThread().getName() + "- start --" + System.currentTimeMillis());
+    }
+
+    @Override
+    public void result(boolean success, String param, WorkResult<User> workResult) {
+        System.out.println("worker0 的结果是：" + workResult.getResult());
+    }
+
+}
diff --git a/src/main/java/com/tianyalei/test/depend/ParWorker1.java b/src/main/java/com/tianyalei/test/depend/ParWorker1.java
new file mode 100755
index 0000000..c700906
--- /dev/null
+++ b/src/main/java/com/tianyalei/test/depend/ParWorker1.java
@@ -0,0 +1,40 @@
+package com.tianyalei.test.depend;
+
+
+import com.tianyalei.async.callback.ICallback;
+import com.tianyalei.async.callback.IWorker;
+import com.tianyalei.async.worker.WorkResult;
+
+/**
+ * @author wuweifeng wrote on 2019-11-20.
+ */
+public class ParWorker1 implements IWorker<WorkResult<User>, User>, ICallback<WorkResult<User>, User> {
+
+    @Override
+    public User action(WorkResult<User> result) {
+        System.out.println("par1的入参来自于par0： " + result.getResult());
+        try {
+            Thread.sleep(1000);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+        return new User("user1");
+    }
+
+
+    @Override
+    public User defaultValue() {
+        return new User("default User");
+    }
+
+    @Override
+    public void begin() {
+        //System.out.println(Thread.currentThread().getName() + "- start --" + System.currentTimeMillis());
+    }
+
+    @Override
+    public void result(boolean success, WorkResult<User> param, WorkResult<User> workResult) {
+        System.out.println("worker1 的结果是：" + workResult.getResult());
+    }
+
+}
diff --git a/src/main/java/com/tianyalei/test/depend/ParWorker2.java b/src/main/java/com/tianyalei/test/depend/ParWorker2.java
new file mode 100755
index 0000000..20c5dde
--- /dev/null
+++ b/src/main/java/com/tianyalei/test/depend/ParWorker2.java
@@ -0,0 +1,40 @@
+package com.tianyalei.test.depend;
+
+
+import com.tianyalei.async.callback.ICallback;
+import com.tianyalei.async.callback.IWorker;
+import com.tianyalei.async.worker.WorkResult;
+
+/**
+ * @author wuweifeng wrote on 2019-11-20.
+ */
+public class ParWorker2 implements IWorker<WorkResult<User>, String>, ICallback<WorkResult<User>, String> {
+
+    @Override
+    public String action(WorkResult<User> result) {
+        System.out.println("par2的入参来自于par1： " + result.getResult());
+        try {
+            Thread.sleep(1000);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+        return result.getResult().getName();
+    }
+
+
+    @Override
+    public String defaultValue() {
+        return "default";
+    }
+
+    @Override
+    public void begin() {
+        //System.out.println(Thread.currentThread().getName() + "- start --" + System.currentTimeMillis());
+    }
+
+    @Override
+    public void result(boolean success, WorkResult<User> param, WorkResult<String> workResult) {
+        System.out.println("worker2 的结果是：" + workResult.getResult());
+    }
+
+}
diff --git a/src/main/java/com/tianyalei/test/depend/Test.java b/src/main/java/com/tianyalei/test/depend/Test.java
new file mode 100644
index 0000000..32cf9c9
--- /dev/null
+++ b/src/main/java/com/tianyalei/test/depend/Test.java
@@ -0,0 +1,39 @@
+package com.tianyalei.test.depend;
+
+import com.tianyalei.async.executor.Async;
+import com.tianyalei.async.group.WorkerWrapper;
+import com.tianyalei.async.worker.WorkResult;
+
+import java.util.concurrent.ExecutionException;
+
+
+/**
+ * 后面请求依赖于前面请求的执行结果
+ * @author wuweifeng wrote on 2019-12-26
+ * @version 1.0
+ */
+public class Test {
+
+    public static void main(String[] args) throws ExecutionException, InterruptedException {
+        ParWorker w = new ParWorker();
+        ParWorker1 w1 = new ParWorker1();
+        ParWorker2 w2 = new ParWorker2();
+
+        WorkerWrapper<String, User> workerWrapper = new WorkerWrapper<>(w, "0", w);
+        //虽然尚未执行，但是也可以先取得结果的引用，作为下一个任务的入参
+        WorkResult<User> result = workerWrapper.getWorkResult();
+
+        WorkerWrapper<WorkResult<User>, User> workerWrapper1 = new WorkerWrapper<>(w1, result, w1);
+        WorkResult<User> result1 = workerWrapper1.getWorkResult();
+
+        WorkerWrapper<WorkResult<User>, String> workerWrapper2 = new WorkerWrapper<>(w2, result1, w2);
+
+        workerWrapper.addNext(workerWrapper1);
+        workerWrapper1.addNext(workerWrapper2);
+
+        Async.beginWork(3500, workerWrapper);
+
+        System.out.println(workerWrapper2.getWorkResult());
+        Async.shutDown();
+    }
+}
diff --git a/src/main/java/com/tianyalei/test/depend/User.java b/src/main/java/com/tianyalei/test/depend/User.java
new file mode 100644
index 0000000..b0be501
--- /dev/null
+++ b/src/main/java/com/tianyalei/test/depend/User.java
@@ -0,0 +1,29 @@
+package com.tianyalei.test.depend;
+
+/**
+ * 一个包装类
+ * @author wuweifeng wrote on 2019-12-26
+ * @version 1.0
+ */
+public class User {
+    private String name;
+
+    public User(String name) {
+        this.name = name;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public String toString() {
+        return "User{" +
+                "name='" + name + '\'' +
+                '}';
+    }
+}
diff --git a/src/main/java/com/tianyalei/test/parallel/TestPar.java b/src/main/java/com/tianyalei/test/parallel/TestPar.java
index 7791608..d609b37 100755
--- a/src/main/java/com/tianyalei/test/parallel/TestPar.java
+++ b/src/main/java/com/tianyalei/test/parallel/TestPar.java
@@ -10,7 +10,7 @@ import java.util.concurrent.ExecutionException;
 import static com.tianyalei.async.executor.Async.getThreadCount;
 
 /**
- * 串行测试
+ * 并行测试
  *
  * @author wuweifeng wrote on 2019-11-20.
  */