轉載自：

Lets say we want to install (or downgrade to) node 0.6.19 instead of the newest version.

If you already have node, uninstall current version with:

$ brew uninstall node

Then search for available versions of the formula:

$ brew versions node
0.8.3    git checkout 31f8d9f Library/Formula/node.rb
 

0.8.2    git checkout 50ae8e4 Library/Formula/node.rb
0.8.1    git checkout 9ff0a1d Library/Formula/node.rb
0.8.0    git checkout 01f8006 Library/Formula/node.rb
0.6.19   git checkout 83988e4 Library/Formula/node.rb

Now checkout the desired version. Assuming you're at /usr/local/:

$ git checkout 83988e4 Library/Formula/node.rb
 

Finally install node:

$ brew install node

Done!