diff --git a/typescript/core/func/string.ts b/typescript/core/func/string.ts
new file mode 100644
index 0000000000..fae4d7d669
--- /dev/null
+++ b/typescript/core/func/string.ts
@@ -0,0 +1,13 @@
+export declare type _startWith = (str: string, startTag: string) => boolean;
+
+export declare type _endWith = (str: string, endTag: string) =>  boolean;
+
+export declare type _getQuery = (str: string, name: string) =>  string|null;
+
+export declare type _appendQuery = (str: string, paras: {[key: string]: string|number}) => string;
+
+export declare type _replaceAll = (str: string, s1: string, s2: string) => string;
+
+export declare type _perfectStart = (str: string, start: string) => string;
+
+export declare type _allIndexOf = (str: string, sub: string) => number[];
diff --git a/typescript/index.ts b/typescript/index.ts
index 95723ce610..b3d9cae20a 100644
--- a/typescript/index.ts
+++ b/typescript/index.ts
@@ -1,6 +1,7 @@
 import { _addI18n, _i18nText } from "./core/i18n";
 import { _OB } from "./core/ob";
 import { _pushArray, _pushDistinct, _pushDistinctArray} from "./core/func/array";
+import {_startWith, _allIndexOf, _appendQuery, _endWith, _getQuery, _perfectStart, _replaceAll} from "./core/func/string";
 
 export declare module BI {
     namespace i18n {
@@ -13,4 +14,12 @@ export declare module BI {
     const pushArray: _pushArray;
     const pushDistinct: _pushDistinct;
     const pushDistinctArray: _pushDistinctArray;
+
+    const startWith: _startWith;
+    const endWith: _endWith;
+    const allIndexOf: _allIndexOf;
+    const appendQuery: _appendQuery;
+    const getQuery: _getQuery;
+    const perfectStart: _perfectStart;
+    const replaceAll: _replaceAll;
 }