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:
- Start Eclipse, then select Help > Install New Software.
- Click Add, in the top-right corner.
- 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.
- Click OK.
- In the Available Software dialog, select the checkbox next to Developer Tools and click Next.
- In the next window, you‘ll see a list of the tools to be downloaded. Click Next.
- 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.
- 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