diff --git a/components/dropdown/demo/sub-menu.md b/components/dropdown/demo/sub-menu.md
index b1f163a87..92e2ae27c 100644
--- a/components/dropdown/demo/sub-menu.md
+++ b/components/dropdown/demo/sub-menu.md
@@ -15,6 +15,8 @@ The menu has multiple levels.
       Cascading menu <a-icon type="down" />
     </a>
     <a-menu slot="overlay">
+      <a-menu-item>1st menu item</a-menu-item>
+      <a-menu-item>2nd menu item</a-menu-item>
       <a-sub-menu title="sub menu" key="test">
         <a-menu-item>3rd menu item</a-menu-item>
         <a-menu-item>4th menu item</a-menu-item>
diff --git a/components/dropdown/dropdown.vue b/components/dropdown/dropdown.vue
index 04d5524bc..fa2c9ee19 100644
--- a/components/dropdown/dropdown.vue
+++ b/components/dropdown/dropdown.vue
@@ -47,6 +47,7 @@ const Dropdown = {
       props: {
         mode: 'vertical',
         selectable,
+        isRootMenu: false,
       },
     })
     const dropdownProps = {
diff --git a/components/menu/index.vue b/components/menu/index.vue
index 68b034420..02bec4583 100644
--- a/components/menu/index.vue
+++ b/components/menu/index.vue
@@ -27,9 +27,11 @@ export const menuProps = {
   multiple: PropTypes.bool,
   inlineIndent: PropTypes.number.def(24),
   inlineCollapsed: PropTypes.bool,
+  isRootMenu: PropTypes.bool.def(true),
 }
 
 export default {
+  name: 'Menu',
   props: menuProps,
   Divider,
   Item,
diff --git a/components/menu/src/Menu.vue b/components/menu/src/Menu.vue
index 1a6f2f006..d519599f5 100644
--- a/components/menu/src/Menu.vue
+++ b/components/menu/src/Menu.vue
@@ -24,7 +24,7 @@ const Menu = {
       sOpenKeys = props.openKeys || []
     }
 
-    this.isRootMenu = true
+    // this.isRootMenu = true
     return {
       sSelectedKeys,
       sOpenKeys,
@@ -177,7 +177,7 @@ const Menu = {
         openKeys: state.sOpenKeys,
         selectedKeys: state.sSelectedKeys,
         triggerSubMenuAction: this.$props.triggerSubMenuAction,
-        isRootMenu: true,
+        isRootMenu: this.isRootMenu,
       }
       return this.renderCommonMenuItem(c, i, subIndex, extraProps)
     },
diff --git a/components/menu/src/commonPropsType.js b/components/menu/src/commonPropsType.js
index d8f885395..e5e29f2db 100644
--- a/components/menu/src/commonPropsType.js
+++ b/components/menu/src/commonPropsType.js
@@ -22,4 +22,5 @@ export default {
   openTransitionName: PropTypes.string,
   forceSubMenuRender: PropTypes.bool,
   selectable: PropTypes.bool,
+  isRootMenu: PropTypes.bool,
 }