diff --git a/src/base/combination/tab.js b/src/base/combination/tab.js
index 893513721..90a788a17 100644
--- a/src/base/combination/tab.js
+++ b/src/base/combination/tab.js
@@ -86,15 +86,18 @@ BI.Tab = BI.inherit(BI.Widget, {
 
     created: function () {
         var self = this, o = this.options;
-        if (o.showIndex !== false) {
-            if (BI.isFunction(o.showIndex)) {
-                var v = this.__watch(o.showIndex, function (context, newValue) {
-                    self.setSelect(newValue);
-                });
-                this.setSelect(v);
-            } else {
-                this.setSelect(o.showIndex);
-            }
+
+        var showIndex;
+        if (BI.isFunction(o.showIndex)) {
+            showIndex = this.__watch(o.showIndex, function (context, newValue) {
+                self.setSelect(newValue);
+            });
+        } else {
+            showIndex = o.showIndex;
+        }
+
+        if (showIndex !== false) {
+            this.setSelect(showIndex);
         }
     },
 
@@ -135,7 +138,7 @@ BI.Tab = BI.inherit(BI.Widget, {
     getTab: function (v) {
         this._assertCard(v);
 
-return this.layout.getCardByName(v);
+        return this.layout.getCardByName(v);
     },
 
     setValue: function (v) {
diff --git a/typescript/core/widget.ts b/typescript/core/widget.ts
index 0a1b63246..4c1fc9d2f 100644
--- a/typescript/core/widget.ts
+++ b/typescript/core/widget.ts
@@ -42,8 +42,8 @@ export interface _Widget extends _OB {
     element: {
         width(): number;
         height(): number;
-        width(width: number | string): _Widget['element'];
-        height(height: number | string): _Widget['element'];
+        width(width: number | string): _Widget["element"];
+        height(height: number | string): _Widget["element"];
         [key: string]: any;
     };
 
@@ -110,7 +110,7 @@ export interface _Widget extends _OB {
     /**
      * 更新前
      */
-    shouldUpdate?(): void;
+    shouldUpdate?(...args: any[]): void;
 
     /**
      * 更新
@@ -449,8 +449,8 @@ export declare class Widget extends OB {
     element: {
         width(): number;
         height(): number;
-        width(width: number | string): Widget['element'];
-        height(height: number | string): Widget['element'];
+        width(width: number | string): Widget["element"];
+        height(height: number | string): Widget["element"];
         [key: string]: any;
     };
 
@@ -783,6 +783,11 @@ export declare class Widget extends OB {
      */
     _unMount(): void;
 
+    /**
+     * watch响应式数据
+     */
+    __watch<T extends (...args: any) => any>(getter: T, handler: Function, options?: Obj): ReturnType<T>
+
     /**
      * hang元素
      */