diff --git a/.flowconfig b/.flowconfig
index 4bef7624d38..1a6d8a725c7 100644
--- a/.flowconfig
+++ b/.flowconfig
@@ -4,6 +4,7 @@
 .*/build/.*
 .*/examples/.*
 .*/benchmarks/.*
+.*/decls/.*
 
 [include]
 
diff --git a/decls/vue_v2.2.x/flow_v0.39.x-/vue_v2.2.x.js b/decls/vue_v2.2.x/flow_v0.39.x-/vue_v2.2.x.js
new file mode 100644
index 00000000000..7c238bf8d22
--- /dev/null
+++ b/decls/vue_v2.2.x/flow_v0.39.x-/vue_v2.2.x.js
@@ -0,0 +1,288 @@
+declare type $npm$Vue$Config = {
+  silent: boolean;
+  optionMergeStrategies: { [key: string]: Function };
+  devtools: boolean;
+  errorHandler: ?(err: Error, vm: Vue, info: string) => void;
+  ignoredElements: Array<string>;
+  keyCodes: { [key: string]: number | Array<number> };
+}
+
+declare type $npm$Vue$Constructor = Class<any>;
+
+declare type $npm$Vue$Component = typeof Vue | $npm$Vue$FunctionalComponentOptions | $npm$Vue$ComponentOptions;
+
+declare type $npm$Vue$AsyncComponent = (
+  resolve: (component: $npm$Vue$Component) => void,
+  reject: (reason?: any) => void
+) => Promise<$npm$Vue$Component> | $npm$Vue$Component | void;
+
+declare interface $npm$Vue$PropOptions {
+  type?: $npm$Vue$Constructor | Array<$npm$Vue$Constructor>;
+  required?: boolean;
+  default?: any;
+  validator?: (value: any) => boolean;
+}
+
+// TODO:
+declare type $npm$Vue$CreateElement = {
+  (): $npm$Vue$VNode;
+  (tag: string, children: $npm$Vue$VNodeChildren): $npm$Vue$VNode;
+  (tag: string, data?: $npm$Vue$VNodeData, children?: $npm$Vue$VNodeChildren): $npm$Vue$VNode;
+  (tag: $npm$Vue$Component, children: $npm$Vue$VNodeChildren): $npm$Vue$VNode;
+  (tag: $npm$Vue$Component, data?: $npm$Vue$VNodeData, children?: $npm$Vue$VNodeChildren): $npm$Vue$VNode;
+  (tag: $npm$Vue$AsyncComponent, children: $npm$Vue$VNodeChildren): $npm$Vue$VNode;
+  (tag: $npm$Vue$AsyncComponent, data?: $npm$Vue$VNodeData, children?: $npm$Vue$VNodeChildren): $npm$Vue$VNode;
+}
+
+declare type $npm$Vue$RenderContext = {
+  props: any;
+  children: Array<$npm$Vue$VNode>;
+  slots(): any;
+  data: $npm$Vue$VNodeData;
+  parent: Vue;
+}
+
+declare interface $npm$Vue$ComputedOptions {
+  get?: () => any;
+  set?: (value: any) => void;
+  cache?: boolean;
+}
+
+declare type $npm$Vue$WatchHandler = (val: any, oldVal: any) => void;
+
+declare interface $npm$Vue$WatchOptions {
+  deep?: boolean;
+  immediate?: boolean;
+}
+
+declare type $npm$Vue$FunctionalComponentOptions = {
+  props?: Array<string> | { [key: string]: $npm$Vue$PropOptions | $npm$Vue$Constructor | Array<$npm$Vue$Constructor> };
+  functional: boolean;
+  render: (createElement: $npm$Vue$CreateElement, context: $npm$Vue$RenderContext) => $npm$Vue$VNode;
+  name?: string
+}
+
+declare type $npm$Vue$ComponentOptions = {
+  // Options / Data
+  data?: (() => Object) | Object;
+  //data?: { $call?: () => Object };
+  props?: Array<string> | { [key: string]: $npm$Vue$PropOptions | $npm$Vue$Constructor | Array<$npm$Vue$Constructor> };
+  propsData?: Object;
+  computed?: { [key: string]: (() => any) | $npm$Vue$ComputedOptions };
+  methods?: { [key: string]: () => any };
+  watch?: { [key: string]: ({ handler: $npm$Vue$WatchHandler } & $npm$Vue$WatchOptions) | $npm$Vue$WatchHandler | string };
+
+  // Options /DOM
+  el?: Element | string;
+  template?: string;
+  render?: (createElement: $npm$Vue$CreateElement) => $npm$Vue$VNode;
+  //staticRenderFns?: (createElement: $npm$Vue$CreateElement) => Array<$npm$Vue$VNode>;
+
+  // Options / Lifecycle
+  beforeCreate?: Function;
+  created?: Function;
+  beforeDestroy?: Function;
+  destroyed?: Function;
+  beforeMount?: Function;
+  mounted?: Function;
+  beforeUpdate?: Function;
+  updated?: Function;
+  activated?: Function;
+  deactivated?: Function;
+
+  // Options / Assets
+  directives?: { [key: string]: $npm$Vue$DirectiveOptions | $npm$Vue$DirectiveFunction };
+  components?: { [key: string]: $npm$Vue$Component | $npm$Vue$AsyncComponent };
+  //transitions?: { [key: string]: Object };
+  filters?: { [key: string]: Function };
+
+  // Options / Others
+  parent?: Vue;
+  mixins?: Array<$npm$Vue$ComponentOptions | typeof Vue>;
+  name?: string;
+  extends?: Array<$npm$Vue$ComponentOptions | typeof Vue>;
+  delimiters?: [string, string];
+  functional?: boolean;
+}
+
+declare type $npm$Vue$ScopedSlot = (props: any) => $npm$Vue$VNodeChildrenArrayContents | string;
+
+declare interface $npm$Vue$VNodeComponentOptions {
+  Ctor: typeof Vue;
+  propsData?: Object;
+  listeners?: Object;
+  children?: $npm$Vue$VNodeChildren;
+  tag?: string;
+}
+
+declare type $npm$Vue$VNodeChildren = $npm$Vue$VNodeChildrenArrayContents | [$npm$Vue$ScopedSlot] | string;
+
+declare interface $npm$Vue$VNodeChildrenArrayContents {
+  [x: number]: $npm$Vue$VNode | string | $npm$Vue$VNodeChildren;
+}
+
+declare interface $npm$Vue$VNodeData {
+  key?: string | number;
+  slot?: string;
+  scopedSlots?: { [key: string]: $npm$Vue$ScopedSlot };
+  ref?: string;
+  tag?: string;
+  staticClass?: string;
+  class?: any;
+  staticStyle?: { [key: string]: any };
+  style?: Array<Object> | Object;
+  props?: { [key: string]: any };
+  attrs?: { [key: string]: any };
+  domProps?: { [key: string]: any };
+  hook?: { [key: string]: Function };
+  on?: { [key: string]: Function | Array<Function> };
+  nativeOn?: { [key: string]: Function | Array<Function> };
+  transition?: Object;
+  show?: boolean;
+  inlineTemplate?: {
+    render: Function;
+    staticRenderFns: Array<Function>;
+  };
+  directives?: Array<$npm$Vue$VNodeDirective>;
+  keepAlive?: boolean;
+}
+
+declare interface $npm$Vue$VNode {
+  tag?: string;
+  data?: $npm$Vue$VNodeData;
+  children?: Array<$npm$Vue$VNode>;
+  text?: string;
+  elm?: Node;
+  ns?: string;
+  context?: Vue;
+  key?: string | number;
+  componentOptions?: $npm$Vue$VNodeComponentOptions;
+  componentInstance?: Vue;
+  parent?: $npm$Vue$VNode;
+  raw?: boolean;
+  isStatic?: boolean;
+  isRootInsert: boolean;
+  isComment: boolean;
+}
+
+declare interface $npm$Vue$VNodeDirective {
+  name: string;
+  value: any;
+  oldValue: any;
+  expression: any;
+  arg: string;
+  modifiers: { [key: string]: boolean };
+}
+
+declare type $npm$Vue$DirectiveFunction = (
+  el: HTMLElement,
+  binding: $npm$Vue$VNodeDirective,
+  vnode: $npm$Vue$VNode,
+  oldVnode: $npm$Vue$VNode
+) => void;
+
+declare interface $npm$Vue$DirectiveOptions {
+  bind?: $npm$Vue$DirectiveFunction;
+  inserted?: $npm$Vue$DirectiveFunction;
+  update?: $npm$Vue$DirectiveFunction;
+  componentUpdated?: $npm$Vue$DirectiveFunction;
+  unbind?: $npm$Vue$DirectiveFunction;
+}
+
+declare type $npm$Vue$PluginFunction = (Vue: typeof Vue, options?: Object) => void;
+
+declare interface $npm$Vue$PluginObject {
+  install: $npm$Vue$PluginFunction;
+}
+
+declare class Vue {
+  constructor(options?: $npm$Vue$ComponentOptions): void;
+
+  // Global Config
+  static config: $npm$Vue$Config;
+
+  // Global API
+  static extend(options: $npm$Vue$FunctionalComponentOptions | $npm$Vue$ComponentOptions): typeof Vue;
+  static nextTick(cb: Function, context?: Object): void;
+  static nextTick(): Promise<void>;
+  static set<T>(obj: Object | Array<T>, key: string, value: T): T;
+  static delete(object: Object, key: string): void;
+  static directive(id: string, definition?: $npm$Vue$DirectiveOptions | $npm$Vue$DirectiveFunction): $npm$Vue$DirectiveOptions;
+  static filter(id: string, definition?: Function): Function;
+  static component(id: string, definition?: $npm$Vue$Component | $npm$Vue$AsyncComponent): typeof Vue;
+
+  static use(plugin: $npm$Vue$PluginObject | $npm$Vue$PluginFunction, options?: Object): void;
+  static mixin(mixin: typeof Vue | $npm$Vue$ComponentOptions): void;
+  static compile(template: string): {
+    render(createElement: $npm$Vue$CreateElement): $npm$Vue$VNode;
+    staticRenderFns: () => Array<$npm$Vue$VNode>;
+  };
+  static version: string;
+
+  // Instance properties
+  $data: Object;
+  $el: HTMLElement;
+  $options: $npm$Vue$ComponentOptions;
+  $parent: Vue | void;
+  $root: Vue;
+  $children: Array<Vue>;
+  $refs: { [key: string]: Vue | Element | Array<$Subtype<Vue>> | Array<$Subtype<Element>>};
+  $slots: { [key: string]: Array<$npm$Vue$VNode> };
+  $scopedSlots: { [key: string]: $npm$Vue$ScopedSlot };
+  $isServer: boolean;
+
+  // Instance Methods / Data
+  $watch(
+    expOrFn: string | Function,
+    callback: $npm$Vue$WatchHandler,
+    options?: $npm$Vue$WatchOptions
+  ): (() => void);
+  //$set<T>(obj: Object | Array<T>, key: string, value: T): T;
+  $set: typeof Vue.set;
+  //$delete (object: Object, key: string): void;
+  $delete: typeof Vue.delete;
+
+  // Instance methods / Event
+  $on(event: string, callback: Function): this;
+  $once(event: string, callback: Function): this;
+  $off(event?: string, callback?: Function): this;
+  $emit(event: string, ...args: Array<any>): this;
+
+  // Instance methods / Lifecycle
+  $mount(elementOrSelector?: Element | string, hydrating?: boolean): this;
+  $forceUpdate(): void;
+  $nextTick(callback: () => void): void;
+  $nextTick(): Promise<void>;
+  $destroy(): void;
+}
+
+declare module 'vue' {
+  declare type Config = $npm$Vue$Config;
+
+  declare type Component = $npm$Vue$Component;
+  declare type AsyncComponent = $npm$Vue$AsyncComponent;
+
+  declare type ComponentOptions = $npm$Vue$ComponentOptions;
+  declare type FunctionalComponentOptions = $npm$Vue$FunctionalComponentOptions;
+  declare type PropOptions = $npm$Vue$PropOptions;
+
+  declare type ComputedOptions = $npm$Vue$ComputedOptions;
+
+  declare type WatchHandler = $npm$Vue$WatchHandler;
+  declare type WatchOptions = $npm$Vue$WatchOptions;
+
+  declare type DirectiveFunction = $npm$Vue$DirectiveFunction;
+  declare type DirectiveOptions = $npm$Vue$DirectiveOptions;
+
+  declare type VNodeChildren = $npm$Vue$VNodeChildren;
+  declare type VNodeChildrenArrayContents = $npm$Vue$VNodeChildrenArrayContents;
+  declare type VNode = $npm$Vue$VNode;
+  declare type VNodeComponentOptions = $npm$Vue$VNodeComponentOptions;
+  declare type VNodeData = $npm$Vue$VNodeData;
+  declare type VNodeDirective = $npm$Vue$VNodeDirective;
+  declare type CreateElement = $npm$Vue$CreateElement;
+  declare type RenderContext = $npm$Vue$RenderContext;
+
+  declare module.exports: typeof Vue;
+}
+
diff --git a/decls/vue_v2.2.x/test_vue_v2.2.x.js b/decls/vue_v2.2.x/test_vue_v2.2.x.js
new file mode 100644
index 00000000000..7a09bb2bace
--- /dev/null
+++ b/decls/vue_v2.2.x/test_vue_v2.2.x.js
@@ -0,0 +1,8 @@
+/* @flow */
+
+import Vue from 'vue'
+import type { Config } from 'vue'
+
+const config: Config = Vue.config
+
+// TODO: should be more test!!
diff --git a/package.json b/package.json
index 346ed435bda..f92c98e9e03 100644
--- a/package.json
+++ b/package.json
@@ -9,7 +9,8 @@
   "files": [
     "src",
     "dist/*.js",
-    "types/*.d.ts"
+    "types/*.d.ts",
+    "decls/**/*.js"
   ],
   "scripts": {
     "dev": "TARGET=web-full-dev rollup -w -c build/config.js",
@@ -22,7 +23,7 @@
     "build": "node build/build.js",
     "build:ssr": "npm run build -- vue.runtime.common.js,vue-server-renderer",
     "build:weex": "npm run build -- weex-vue-framework,weex-template-compiler",
-    "test": "npm run lint && flow check && npm run test:types && npm run test:cover && npm run test:e2e -- --env phantomjs && npm run test:ssr",
+    "test": "npm run lint && flow check && npm run test:types && npm run test:flow && npm run test:cover && npm run test:e2e -- --env phantomjs && npm run test:ssr",
     "test:unit": "karma start build/karma.unit.config.js",
     "test:cover": "karma start build/karma.cover.config.js",
     "test:e2e": "npm run build -- vue.min.js && node test/e2e/runner.js",
@@ -30,6 +31,7 @@
     "test:ssr": "npm run build:ssr && jasmine JASMINE_CONFIG_PATH=test/ssr/jasmine.json",
     "test:sauce": "npm run sauce -- 0 && npm run sauce -- 1 && npm run sauce -- 2",
     "test:types": "tsc -p ./types/test/tsconfig.json",
+    "test:flow": "flow check --lib decls/vue_v2.2.x/flow_v0.39.x-/vue_v2.2.x.js decls/vue_v2.2.x/test_vue_v2.2.x.js",
     "lint": "eslint src build test",
     "flow": "flow check",
     "sauce": "SAUCE=true karma start build/karma.sauce.config.js",