打开这个网址就可以看到adt的详细信息：  http://developer.android.com/sdk/installing/installing-adt.html   

或者直接在你的eclipse的Help > Install New Software里面add,地址直接输入

https://dl-ssl.google.com/android/eclipse/

官方步骤：

Download the ADT Plugin

To add the ADT plugin to Eclipse:

1. Start Eclipse, then select Help > Install New Software.
2. Click Add, in the top-right corner.
3. In the Add Repository dialog that appears, enter "ADT Plugin" for the Name and the following URL for theLocation:

   https://dl-ssl.google.com/android/eclipse/

   Note: The Android Developer Tools update site requires a secure connection. Make sure the update site URL you enter starts with HTTPS.

4. Click OK.
5. In the Available Software dialog, select the checkbox next to Developer Tools and click Next.
6. In the next window, you‘ll see a list of the tools to be downloaded. Click Next.
7. Read and accept the license agreements, then click Finish.

   If you get a security warning saying that the authenticity or validity of the software can‘t be established, click OK.

8. When the installation completes, restart Eclipse.

这里可以下载我下载的最新版本adt，版本是23.03，你也可以直接导入

http://yun.baidu.com/share/link?shareid=237171126&uk=3794660469