If you mean the small »circles« that are arranged around the big circle you could achieve that with a hard brush with the appropriate Spacing set in the Brush Panel.
Or you could create a Path with two opposing small circles, copy/paste those, transform them (command-T) and then use Transform Again (command-shift-T) as many times as necessary. Edit: And then use the Path as a Vector Mask for a Solid Color Layer for example …
Or you could create a circle Layer and use a Script.
http://forums.adobe.com/message/4195530#4195530
