There's no official way to import Facebook contacts into Google+, but you can add your Facebook contacts to Yahoo through Facebook Connect, and then connect Yahoo to Google+. A long way around, but it works...
Here’s a trick to get everyone from your Facebook social graph into Google Plus:
1. Sign up for a Yahoo! Mail account, and import all of your Facebook contacts. Click “Contacts” at the top, and then “Import Contacts”. Authorize Facebook access to your Yahoo! address book.
2. Log in to Google Plus (http://plus.google.com
) and navigate to your “Circles” (https://plus.google.com/circles
3. Click “Find and Invite”, and then click Yahoo! Import your Facebook friends to the “Suggestions” section.
4. Drag everyone into the appropriate “Circle”. See screenshot below.