I assume you're referencing Blogger (
Referer spam has been a problem on Blogger and other blogging sites for a very long time. Unfortunately there isn't an effective way to block it because it's very difficult to distinguish legitimate referers from spammers.
Editing your robots.txt file will not help because spammers often use fake user-agent strings and do not observe the robots.txt protocol.
Referer spam will not impact third-party statistics/analytics however, as discussed below, so use one to view actual traffic reports:
Referer Spam Does Not Represent Real Traffic, To Our Blogs
The most common advice given is:
Do not publish the contents of your traffic logs or list referers in your content.
Do not click on links in your traffic logs that you don't recognize.
Be patient and let Google (or other blog service) block referer spam over time.