Discipline construction is not just the foundation, but also the level of the entire li? brary science education.[Method/process] Through nearly a hundred years of development，China’s library science education has achieved remarkable achievement，which not only is influenced by knowledge system，is still influenced by library cause in different stages. Therefore，taking knowledge system and library cause as a view，by studying the law of logical evolution，the aim of this paper is to describe the trends and regularity of a discipline，to explain logical pro? duction process which library cause high-quality development with construction of first-class discipline of library sci? ence achieve coordination.[Result/conclusion] The results show that since the founding of the People's Republic of China，library science has gone through four stages: affected by library cause development by application logic、inde? pendent growth stage of discipline、isomorphic symbiosis by application logic and the discipline logic、loose coupling and coordination. According to the discipline evolution law、characteristic, the article concludes the development path of reconstructing relationships of library science and library cause as follows：change the logic philosophy of discipline construction、reestablish the loose coupling relationship；strengthening connotation construction to improve the efficien? cy of supply；fulfilling the new mission of library cause to improve adaptability of external environment of discipline construction of library science；improving internal adaptability of discipline construction by using new technique 、new environment、new industry.