diff --git a/components/tooltip/demo/basic.vue b/components/tooltip/demo/basic.vue
index c9169f442..a1e0451d3 100644
--- a/components/tooltip/demo/basic.vue
+++ b/components/tooltip/demo/basic.vue
@@ -1,11 +1,11 @@
 <template>
   <div>
     <tool-tip
-      placement="bottom"
+      placement="top"
       :title="showText">
       <h1 @click="boom" style="display: inline-block">This is just a test, put your cursor here</h1>
     </tool-tip>
-    <ant-button>2223</ant-button>
+    <ant-button>{{showText}}</ant-button>
     <div class="box">
       <table>
         <tr v-for="(tr, index) in table" :key="index">
@@ -19,8 +19,8 @@
 </template>
 
 <script>
-  import { ToolTip, Button } from '../../../components'
-  import '../../../components/button/style'
+  import { ToolTip, Button } from 'antd'
+  import 'antd/button/style'
 	export default {
 		name: 'tooltip-basic',
 		data() {
@@ -38,15 +38,16 @@
 		},
     methods: {
 		  boom() {
-		    this.showText += '3'
+		    if (this.showText.length % 20) {
+          this.showText += '3'
+        } else {
+		      this.showText += ' '
+        }
       }
     },
     components: {
 		  ToolTip,
       AntButton: Button,
-    },
-    beforeUpdate() {
-		  console.info(90909090)
     }
 	}
 </script>
diff --git a/components/tooltip/tooltip.vue b/components/tooltip/tooltip.vue
index e7dfb2353..80068597c 100644
--- a/components/tooltip/tooltip.vue
+++ b/components/tooltip/tooltip.vue
@@ -33,6 +33,7 @@ export default {
       visible: false,
       left: 0,
       top: 0,
+      realPlacement: this.placement,
     }
   },
   computed: {
@@ -44,6 +45,19 @@ export default {
     },
   },
   methods: {
+    checkPosition(popup, text, placement) {
+      let { top, left, bottom, right } = text
+      const reg = /(top|bottom|left|right)(.*)/
+      const [, abstractPos, suffix] = placement.match(reg)
+      console.info(right - left, popup.width)
+      let ret = placement
+      // we can change the position many times
+      if (abstractPos === 'left' && left < popup.width) ret = 'right' + suffix
+      if (abstractPos === 'right' && document.documentElement.clientWidth - right < popup.width) ret = 'left' + suffix
+      if (abstractPos === 'top' && top < popup.height) ret = 'bottom' + suffix
+      if (abstractPos === 'bottom' && document.documentElement.clientHeight - bottom < popup.height) ret = 'left' + suffix
+      return ret
+    },
     mountNode(callback) {
       if (this.vnode) {
         callback()
@@ -64,7 +78,7 @@ export default {
             <transition name="zoom-big">
               <div
                 v-show={that.visible}
-                class={`ant-tooltip ant-tooltip-placement-${that.placement}`}
+                class={`ant-tooltip ant-tooltip-placement-${that.realPlacement}`}
                 style={{ left: this.left + 'px', top: this.top + 'px' }}
               >
                 <div class="ant-tooltip-content">
@@ -146,11 +160,13 @@ export default {
         this.$nextTick(() => {
           const popup = this.vnode.$el.getBoundingClientRect()
           const content = this.$el.getBoundingClientRect()
-          const { left, top } = this.computeOffset(popup, content, this.placement)
+          const place = this.checkPosition(popup, content, this.placement)
+          this.realPlacement = place
+          const { left, top } = this.computeOffset(popup, content, place)
           this.vnode.left = left
           this.vnode.top = top
         })
-        this.onPopupAlign(this.placement, this.$el, this.vnode.$el, { offset: [0,0] })
+        this.onPopupAlign(this.realPlacement, this.$el, this.vnode.$el, { offset: [0,0] })
       })
     },
     hideNode() {
@@ -170,7 +186,7 @@ export default {
     if (!this.vnode) return
     const popup = this.vnode.$el.getBoundingClientRect()
     const content = this.$el.getBoundingClientRect()
-    const { left, top } = this.computeOffset(popup, content, this.placement)
+    const { left, top } = this.computeOffset(popup, content, this.realPlacement)
     this.vnode.left = left
     this.vnode.top = top
   },