Abstract: Aiming at the phenomenon of ＂subject librarian＂,this article analyses it from the name,the work contents,possibility and the practice of ten years.The author thinks that the essence of ＂subject librarian＂is to enhance the subjects construction in library, and not to create a different post.Library should give full play to the librarian＇s whole force in the light of local conditions.

Key words: subjects construction, subject librarian, reference service