A typical install of OS X won't create a .bash_profile for you. When you want to run functions from your command line, this is a must-have.

1. Start up Terminal
2. Type "cd ~/" to go to your home folder
3. Type "touch .bash_profile" to create your new file.
4. Edit .bash_profile with your favorite editor (or you can just type "open -e .bash_profile" to open it in TextEdit.
5. contents：export ANDROID_HOME="/usr/local/adt/sdk"
6. Type ". .bash_profile" to reload .bash_profile and update any functions you add.

PS：

在MAC系统中，自带的jdk的安装路径默认目录是：/System/Libray/Frameworks /JavaVM.Framwork/。

export JAVA_HOME = "/System/Libray/Frameworks /JavaVM.Framwork/versions/currentjdk/home"

还可以参考：

http://www.cnblogs.com/mokey/p/3542389.html