diff --git a/.gitignore b/.gitignore
index 8c18a31..29f9b68 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 /node_modules
 /lib
 /yarn.lock
+/.idea
diff --git a/src/index.js b/src/index.js
index 87c7d9f..a17df7a 100644
--- a/src/index.js
+++ b/src/index.js
@@ -23,6 +23,18 @@ const log = (model, constitute, count) => {
   }
 }
 
+// 实现深拷贝的Object.assign
+const deepObjectAssign = (target, source) => {
+  try {
+    if (source) {
+      // 对source进行判空，否则JSON.parse操作会报错： Unexpected token u in JSON at position 0
+      Object.assign(target, JSON.parse(JSON.stringify(source)))
+    }
+  } catch (e) {
+    console.log(e)
+  }
+}
+
 export default function modelExtend(...models) {
   const base = { state: {}, subscriptions: {}, effects: {}, reducers: {}, };
   const stateCache = [];
@@ -38,7 +50,7 @@ export default function modelExtend(...models) {
     acc.namespace = extend.namespace;
     if (typeof extend.state === 'object' && !Array.isArray(extend.state)) {
       check(extend.state, stateCache, stateCount)
-      Object.assign(acc.state, extend.state);
+      deepObjectAssign(acc.state, extend.state);
     } else if ('state' in extend) {
       acc.state = extend.state;
     }
diff --git a/test/index.test.js b/test/index.test.js
index e278586..ab41e3c 100644
--- a/test/index.test.js
+++ b/test/index.test.js
@@ -77,6 +77,24 @@ describe('modelExtend', () => {
     assert.strictEqual(res.state.length, 0);
   });
 
+  it('should deeply merge states when they are objects', () => {
+    const originalModel = {
+      state: {
+        user: {
+          name: 'Benjy',
+        }
+      },
+    }
+    const res = modelExtend(originalModel);
+    originalModel.state.user.name = 'Yuan';
+
+    assert.deepEqual(res.state, {
+      user: {
+        name: 'Benjy',
+      }
+    });
+  });
+
   it('should log 2 times of state overwritten log', () => {
     modelExtend({
       state: {