diff --git a/src/main/java/com/diguage/truman/concurrent/SynchronizedTest.java b/src/main/java/com/diguage/truman/concurrent/SynchronizedTest.java
index e9140bb..f4f4709 100644
--- a/src/main/java/com/diguage/truman/concurrent/SynchronizedTest.java
+++ b/src/main/java/com/diguage/truman/concurrent/SynchronizedTest.java
@@ -1,17 +1,72 @@
 package com.diguage.truman.concurrent;
 
+import org.junit.jupiter.api.Test;
+
+import java.util.concurrent.locks.LockSupport;
+
+import static com.diguage.truman.concurrent.SynchronizedTest.SynMain.*;
+
 /**
  * @author D瓜哥, https://www.diguage.com/
  * @since 2020-04-08 19:26
  */
 public class SynchronizedTest {
-    public synchronized void lockMethod() {
-        System.out.println("lock method");
+  public synchronized void lockMethod() {
+    System.out.println("lock method");
+  }
+
+  public void lockObject() {
+    synchronized (this) {
+      System.out.println("lock object");
+    }
+  }
+
+  @Test
+  public void testInstanceLock() {
+    SynMain main = new SynMain();
+    new Thread(main::getInstanceLock1).start();
+    new Thread(main::getInstanceLock2).start();
+    new Thread(SynMain::getStaticLock1).start();
+    new Thread(SynMain::getStaticLock2).start();
+    LockSupport.park();
+  }
+
+
+  public static class SynMain {
+    public static synchronized void getStaticLock1() {
+      System.out.println("getStaticLock1 get lock, running...");
+      try {
+        Thread.sleep(Integer.MAX_VALUE);
+      } catch (InterruptedException e) {
+        e.printStackTrace();
+      }
+    }
+
+    public static synchronized void getStaticLock2() {
+      System.out.println("getStaticLock2 get lock, running...");
+      try {
+        Thread.sleep(Integer.MAX_VALUE);
+      } catch (InterruptedException e) {
+        e.printStackTrace();
+      }
+    }
+
+    public synchronized void getInstanceLock1() {
+      System.out.println("getInstanceLock1 get lock, running...");
+      try {
+        Thread.sleep(Integer.MAX_VALUE);
+      } catch (InterruptedException e) {
+        e.printStackTrace();
+      }
     }
 
-    public void lockObject() {
-        synchronized (this) {
-            System.out.println("lock object");
-        }
+    public synchronized void getInstanceLock2() {
+      System.out.println("getInstanceLock2 get lock, running...");
+      try {
+        Thread.sleep(Integer.MAX_VALUE);
+      } catch (InterruptedException e) {
+        e.printStackTrace();
+      }
     }
+  }
 }