diff --git a/README.md b/README.md
index 2d552bfc16..8da9aed86e 100755
--- a/README.md
+++ b/README.md
@@ -168,6 +168,7 @@ List of Definitions
 * [Moment.js](https://github.com/timrwood/moment) (by [Michael Lakerveld](https://github.com/Lakerfield))
 * [MongoDB](http://mongodb.github.io/node-mongodb-native/) (from TypeScript samples, updated by [Niklas Mollenhauer](https://github.com/nikeee))
 * [Mousetrap](http://craig.is/killing/mice) (by [Dániel Tar](https://github.com/qcz))
+* [msgpack.js](https://github.com/uupaa/msgpack.js) (by [Shinya Mochizuki](https://github.com/enrapt-mochizuki))
 * [Mustache.js](https://github.com/janl/mustache.js) (by [Boris Yankov](https://github.com/borisyankov))
 * [Node.js](http://nodejs.org/) (from TypeScript samples)
 * [node_redis](https://github.com/mranney/node_redis) (by [Boris Yankov](https://github.com/borisyankov))
diff --git a/msgpack/msgpack-tests.ts b/msgpack/msgpack-tests.ts
new file mode 100644
index 0000000000..1a4b2eb396
--- /dev/null
+++ b/msgpack/msgpack-tests.ts
@@ -0,0 +1,28 @@
+/// <reference path="msgpack.d.ts" />
+
+var packed = msgpack.pack("");
+msgpack.unpack(packed);
+
+var packedString = msgpack.pack("", true);
+msgpack.unpack(packedString);
+
+var url = "http://example.com";
+
+var uploadOption = {
+  data: "",
+  worker: false,
+  timeout: 10,
+  before: (xhr: XMLHttpRequest, option: MsgPackUploadOption) => { },
+  after: (xhr: XMLHttpRequest, option: MsgPackUploadOption, result: MsgPackCallbackResult) => { }
+};
+var uploadCallback = (data: string, option: MsgPackUploadOption, result: MsgPackCallbackResult) => { };
+msgpack.upload(url, uploadOption, uploadCallback);
+
+var downloadOption = {
+  worker: false,
+  timeout: 10,
+  before: (xhr: XMLHttpRequest, option: MsgPackDownloadOption) => { },
+  after: (xhr: XMLHttpRequest, option: MsgPackDownloadOption, result: MsgPackCallbackResult) => { }
+};
+var downloadCallback = (data: any, option: MsgPackDownloadOption, result: MsgPackCallbackResult) => { };
+msgpack.download(url, downloadOption, downloadCallback);
diff --git a/msgpack/msgpack.d.ts b/msgpack/msgpack.d.ts
new file mode 100644
index 0000000000..ff6eb5b72c
--- /dev/null
+++ b/msgpack/msgpack.d.ts
@@ -0,0 +1,83 @@
+// Type definitions for msgpack.js - MessagePack JavaScript Implementation
+// Project: https://github.com/uupaa/msgpack.js/
+// Definitions by: Shinya Mochizuki <https://github.com/enrapt-mochizuki/>
+// Definitions: https://github.com/borisyankov/DefinitelyTyped
+
+interface MsgPackStatic {
+  /**
+   * @param data string or ByteArray.
+   * @param toString return string value if true.
+   *
+   * @return string or ByteArray or false. pack failed if false.
+   */
+  pack(data: any, toString?: boolean): any;
+
+  /**
+   * @param data string or ByteArray.
+   *
+   * @return string or ByteArray or undefined. unpack failed if undefined.
+   */
+  unpack(data: any): any;
+
+  worker: string;
+
+  upload(url: string, option: MsgPackUploadOption, callback: MsgPackUploadCallback): void;
+
+  download(url: string, option: MsgPackDownloadOption, callback: MsgPackDownloadCallback): void;
+}
+
+interface MsgPackUploadOption {
+  /**
+   * string or ByteArray
+   */
+  data: any;
+
+  /**
+   * use WebWorker if true.
+   */
+  worker?: boolean;
+
+  /**
+   * timeout sec.
+   */
+  timeout?: number;
+
+  before?: (xhr: XMLHttpRequest, option: MsgPackUploadOption) => void;
+
+  after?: (xhr: XMLHttpRequest, option: MsgPackUploadOption, result: MsgPackCallbackResult) => void;
+}
+
+interface MsgPackUploadCallback {
+  (data: string, option: MsgPackUploadOption, result: MsgPackCallbackResult): void;
+}
+
+interface MsgPackDownloadOption {
+  /**
+   * use WebWorker if true.
+   */
+  worker?: boolean;
+
+  /**
+   * timeout sec.
+   */
+  timeout?: number;
+
+  before?: (xhr: XMLHttpRequest, option: MsgPackDownloadOption) => void;
+
+  after?: (xhr: XMLHttpRequest, option: MsgPackDownloadOption, result: MsgPackCallbackResult) => void;
+}
+
+interface MsgPackDownloadCallback {
+  /**
+   * @param data string or ByteArray
+   */
+  (data: any, option: MsgPackDownloadCallback, result: MsgPackCallbackResult): void;
+}
+
+interface MsgPackCallbackResult {
+  status: number;
+
+  ok: boolean;
+}
+
+declare var msgpack: MsgPackStatic;