diff --git a/components/tabs/demo/nest.md b/components/tabs/demo/nest.md
index b5198fd2a7f4..44555843b719 100644
--- a/components/tabs/demo/nest.md
+++ b/components/tabs/demo/nest.md
@@ -41,13 +41,13 @@ class Demo extends React.Component {
       <div>
         <Select style={{ width: 200 }} onChange={(val) => { this.setState({ parentPos: val }); }}>
           {positionList.map(pos => (
-            <Option value={pos}>Parent - {pos}</Option>
+            <Option key={pos} value={pos}>Parent - {pos}</Option>
           ))}
         </Select>
 
         <Select style={{ width: 200 }} onChange={(val) => { this.setState({ childPos: val }); }}>
           {positionList.map(pos => (
-            <Option value={pos}>Child - {pos}</Option>
+            <Option key={pos} value={pos}>Child - {pos}</Option>
           ))}
         </Select>