This paper analyzing the necessity of the knowledge management for library and the structure of its system; discussing the feature and content of knowledge management and providing some specific counter way to carry out this technique. Knowledge management is not only for knowledge of the information collection, storage, collation and transmission of mechanical management, but also to grasp the relationship between knowledge and logic of the creation of new knowledge to meet the needs of social development management. The research of knowledge management contribute to the libraries to develop a knowledge management model to raise working efficiency. Library as the department in charge of knowledge management and service, should pioneer in its spread and practice, and should combine the innovation and spread of knowledge with technological processes in library to produce high values.