The deal, known as "Mashup with Facebook," essentially adds MySpace to the Facebook Connect program.
There will be a "Connect with Facebook" button listed on MySpace underneath the MySpace sign-in and sign up box.
Once users sign-in, a pop-up menu will ask if it's OK to link their Facebook account with MySpace, which will then add content to their MySpace profile based on the likes and dislikes listed on Facebook.
MySpace's integration will be a "very powerful demonstration of the Facebook platform," said Dan Rose, vice president of partnerships and platform marketing for Facebook.
"This new feature is a great illustration of our strategy around social entertainment and enabling the real-time stream," said Mike Jones, chief executive of MySpace.
"The stream is one of our most popular features on MySpace, and it is now delivering an even richer entertainment experience of relevant content for our users to enjoy."
Once the dominant social-networking site, MySpace now has about 100 million users compared to Facebook's 500 million.
"From our point of view, we've always been a big believer in focused innovation and we think this is a great example of MySpace's new direction, which is very focused on entertainment," Rose said.
While Facebook has millions of users, it also is heavily used in the adult entertainment industry for marketing purposes; many of the same users also belong to XBIZ.net, an adult B2B social networking site.