Professor Chen-Ku Wang devoted to the librarianship on Taiwan more than fifty years. He is the most effective scholar to the librarianship in Taiwan. This paper generalized Professor Wang Chen-ku’s writings on librarianship into five parts such as the essence of library science, the construction of libraries and the national policy, the relationship of library and information services, library management, interlibrary cooperation. There are three characteristics of professor Wang’s scholarly thoughts on librarianship. Firstly, Libraries have to insist on its fundamental values to provide services in the information age. Secondly, Libraries have to emphasize on both the collections of the library and the needs of patrons. Thirdly, Patron is the most important of all in library services.