Abstract: The book is to be used. Achieving the effective knowledge dissemination and promoting the knowledge innovation are the proper meaning of library. Because of the difference of knowledge stocks between the library and the user, there is some knowledge potential difference between the library and the user, which make library disseminate knowledge to users. On the basis of the analysis of library knowledge potential difference connotation, this paper explores the causes of the knowledge dissemination based on the knowledge potential difference, and establishes three modes of library knowledge dissemination, they are the network mode, the circulation mode and hierarchy of needs mode.

Key words: knowledge potential difference; knowledge dissemination; mode of knowledge dissemination; library