Abstract: This paper mainly discusses the coherence between the idea of Long Tail Theory and the thought of the Five Laws of Library Science,and considers that the Long Tail Theory rising in USA not only can bring success to the new economy,but also can give the apocalyptic function to the library service.Understanding the Long Tail Theory thoroughly can accelerate the implementation of the Five Laws of Library Science in the contemporary network environment.

Key words: library;Long Tail Theory;the Five Laws of Library Science;network environment