diff --git a/dist/index.js b/dist/index.js
index e4063f20..e68526ee 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -219,12 +219,16 @@ exports['default'] = _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['d
    * @param  {object} e native event
    */
   onScrollBegin: function onScrollBegin(e) {
+    var _this2 = this;
+
     // update scroll state
     this.setState({
       isScrolling: true
     });
 
-    this.props.onScrollBeginDrag && this.props.onScrollBeginDrag.call(this, e);
+    this.setTimeout(function () {
+      _this2.props.onScrollBeginDrag && _this2.props.onScrollBeginDrag.call(_this2, e);
+    });
   },
 
   /**
@@ -232,7 +236,7 @@ exports['default'] = _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['d
    * @param  {object} e native event
    */
   onScrollEnd: function onScrollEnd(e) {
-    var _this2 = this;
+    var _this3 = this;
 
     // update scroll state
     this.setState({
@@ -241,12 +245,14 @@ exports['default'] = _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['d
 
     this.updateIndex(e.nativeEvent.contentOffset, this.state.dir);
 
+    // Note: `this.setState` is async, so I call the `onMomentumScrollEnd`
+    // in setTimeout to ensure synchronous update `index`
     this.setTimeout(function () {
-      _this2.autoplay();
-    });
+      _this3.autoplay();
 
-    // if `onMomentumScrollEnd` registered will be called here
-    this.props.onMomentumScrollEnd && this.props.onMomentumScrollEnd.call(this, e);
+      // if `onMomentumScrollEnd` registered will be called here
+      _this3.props.onMomentumScrollEnd && _this3.props.onMomentumScrollEnd.call(_this3, e);
+    });
   },
 
   /**
@@ -267,6 +273,7 @@ exports['default'] = _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['d
     } // Note: if touch very very quickly and continuous,
     // the variation of `index` more than 1.
     index = index + diff / step;
+
     if (this.props.loop) {
       if (index <= -1) {
         index = state.total - 1;
@@ -351,7 +358,7 @@ exports['default'] = _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['d
   },
 
   renderButtons: function renderButtons() {
-    var _this3 = this;
+    var _this4 = this;
 
     var nextButton = this.props.nextButton || _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['default'].createElement(
       _React$StyleSheet$Text$View$ScrollView$TouchableOpacity.Text,
@@ -371,7 +378,7 @@ exports['default'] = _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['d
       _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['default'].createElement(
         _React$StyleSheet$Text$View$ScrollView$TouchableOpacity.TouchableOpacity,
         { onPress: function () {
-            return !(!_this3.props.loop && _this3.state.index == 0) && _this3.scrollTo.call(_this3, -1);
+            return !(!_this4.props.loop && _this4.state.index == 0) && _this4.scrollTo.call(_this4, -1);
           } },
         _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['default'].createElement(
           _React$StyleSheet$Text$View$ScrollView$TouchableOpacity.View,
@@ -382,7 +389,7 @@ exports['default'] = _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['d
       _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['default'].createElement(
         _React$StyleSheet$Text$View$ScrollView$TouchableOpacity.TouchableOpacity,
         { onPress: function () {
-            return !(!_this3.props.loop && _this3.state.index == _this3.state.total - 1) && _this3.scrollTo.call(_this3, 1);
+            return !(!_this4.props.loop && _this4.state.index == _this4.state.total - 1) && _this4.scrollTo.call(_this4, 1);
           } },
         _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['default'].createElement(
           _React$StyleSheet$Text$View$ScrollView$TouchableOpacity.View,
diff --git a/examples/examples/index.js b/examples/examples/index.js
index 799c0677..2d8c114d 100644
--- a/examples/examples/index.js
+++ b/examples/examples/index.js
@@ -219,12 +219,16 @@ exports['default'] = _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['d
    * @param  {object} e native event
    */
   onScrollBegin: function onScrollBegin(e) {
+    var _this2 = this;
+
     // update scroll state
     this.setState({
       isScrolling: true
     });
 
-    this.props.onScrollBeginDrag && this.props.onScrollBeginDrag.call(this, e);
+    this.setTimeout(function () {
+      _this2.props.onScrollBeginDrag && _this2.props.onScrollBeginDrag.call(_this2, e);
+    });
   },
 
   /**
@@ -232,7 +236,7 @@ exports['default'] = _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['d
    * @param  {object} e native event
    */
   onScrollEnd: function onScrollEnd(e) {
-    var _this2 = this;
+    var _this3 = this;
 
     // update scroll state
     this.setState({
@@ -241,12 +245,14 @@ exports['default'] = _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['d
 
     this.updateIndex(e.nativeEvent.contentOffset, this.state.dir);
 
+    // Note: `this.setState` is async, so I call the `onMomentumScrollEnd`
+    // in setTimeout to ensure synchronous update `index`
     this.setTimeout(function () {
-      _this2.autoplay();
-    });
+      _this3.autoplay();
 
-    // if `onMomentumScrollEnd` registered will be called here
-    this.props.onMomentumScrollEnd && this.props.onMomentumScrollEnd.call(this, e);
+      // if `onMomentumScrollEnd` registered will be called here
+      _this3.props.onMomentumScrollEnd && _this3.props.onMomentumScrollEnd.call(_this3, e);
+    });
   },
 
   /**
@@ -267,6 +273,7 @@ exports['default'] = _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['d
     } // Note: if touch very very quickly and continuous,
     // the variation of `index` more than 1.
     index = index + diff / step;
+
     if (this.props.loop) {
       if (index <= -1) {
         index = state.total - 1;
@@ -351,7 +358,7 @@ exports['default'] = _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['d
   },
 
   renderButtons: function renderButtons() {
-    var _this3 = this;
+    var _this4 = this;
 
     var nextButton = this.props.nextButton || _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['default'].createElement(
       _React$StyleSheet$Text$View$ScrollView$TouchableOpacity.Text,
@@ -371,7 +378,7 @@ exports['default'] = _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['d
       _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['default'].createElement(
         _React$StyleSheet$Text$View$ScrollView$TouchableOpacity.TouchableOpacity,
         { onPress: function () {
-            return !(!_this3.props.loop && _this3.state.index == 0) && _this3.scrollTo.call(_this3, -1);
+            return !(!_this4.props.loop && _this4.state.index == 0) && _this4.scrollTo.call(_this4, -1);
           } },
         _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['default'].createElement(
           _React$StyleSheet$Text$View$ScrollView$TouchableOpacity.View,
@@ -382,7 +389,7 @@ exports['default'] = _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['d
       _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['default'].createElement(
         _React$StyleSheet$Text$View$ScrollView$TouchableOpacity.TouchableOpacity,
         { onPress: function () {
-            return !(!_this3.props.loop && _this3.state.index == _this3.state.total - 1) && _this3.scrollTo.call(_this3, 1);
+            return !(!_this4.props.loop && _this4.state.index == _this4.state.total - 1) && _this4.scrollTo.call(_this4, 1);
           } },
         _React$StyleSheet$Text$View$ScrollView$TouchableOpacity2['default'].createElement(
           _React$StyleSheet$Text$View$ScrollView$TouchableOpacity.View,
diff --git a/examples/examples/swiper.js b/examples/examples/swiper.js
index 20d75ed5..09906e2d 100644
--- a/examples/examples/swiper.js
+++ b/examples/examples/swiper.js
@@ -60,11 +60,12 @@ var swiper = React.createClass({
         </Swiper>
 
         <Swiper style={styles.wrapper} height={240}
+          onMomentumScrollEnd={function(){console.log('this.state.index:', this.state.index)}}
           dot={<View style={{backgroundColor:'rgba(0,0,0,.2)', width: 5, height: 5,borderRadius: 4, marginLeft: 3, marginRight: 3, marginTop: 3, marginBottom: 3,}} />}
           activeDot={<View style={{backgroundColor: '#000', width: 8, height: 8, borderRadius: 4, marginLeft: 3, marginRight: 3, marginTop: 3, marginBottom: 3,}} />}
           paginationStyle={{
             bottom: -23, left: null, right: 10,
-          }} loop={false}>
+          }} loop={true}>
           <View style={styles.slide} title={<Text numberOfLines={1}>Aussie tourist dies at Bali hotel</Text>}>
             <Image style={styles.image} source={{uri: 'http://c.hiphotos.baidu.com/image/w%3D310/sign=0dff10a81c30e924cfa49a307c096e66/7acb0a46f21fbe096194ceb468600c338644ad43.jpg'}} />
           </View>
diff --git a/src/index.js b/src/index.js
index d57ef67d..8185118f 100644
--- a/src/index.js
+++ b/src/index.js
@@ -226,7 +226,9 @@ export default React.createClass({
       isScrolling: true
     })
 
-    this.props.onScrollBeginDrag && this.props.onScrollBeginDrag.call(this, e)
+    this.setTimeout(() => {
+      this.props.onScrollBeginDrag && this.props.onScrollBeginDrag.call(this, e)
+    })
   },
 
   /**
@@ -242,12 +244,14 @@ export default React.createClass({
 
     this.updateIndex(e.nativeEvent.contentOffset, this.state.dir)
 
+    // Note: `this.setState` is async, so I call the `onMomentumScrollEnd`
+    // in setTimeout to ensure synchronous update `index`
     this.setTimeout(() => {
       this.autoplay()
-    })
 
-    // if `onMomentumScrollEnd` registered will be called here
-    this.props.onMomentumScrollEnd && this.props.onMomentumScrollEnd.call(this, e)
+      // if `onMomentumScrollEnd` registered will be called here
+      this.props.onMomentumScrollEnd && this.props.onMomentumScrollEnd.call(this, e)
+    })
   },
 
   /**
@@ -268,6 +272,7 @@ export default React.createClass({
     // Note: if touch very very quickly and continuous,
     // the variation of `index` more than 1.
     index = index + diff / step
+
     if(this.props.loop) {
       if(index <= -1) {
         index = state.total - 1