[Purpose/significance] Taking Mr. Meng Liansheng as a case, this paper explores his library and information professional practice, related research and academic influence since the end of 1970s. The purpose is to review the development of modern librarianship in China, and comprehend the core elements of library development. [Method/process] Literature content analysis combining with Mr. Meng’s self-reported materials were used to sort out the practice and research achievements of Mr. Meng’s library and information work. A bibliometric method was used to analyze Mr. Meng’s academic influence. [Result/conclusion] He is honest with himself, his practice and research in citation analysis, information resource construction, information service, digital library construction and the construction of the National Science and Technology Library complement each other. His academic influence stems mainly from his problem-oriented practical research and thinking. The professional practice and the related discourse on library and information work by Mr. Meng reflect the six elements throughout the development of library and information work: information resource, technology, management, service, scientific research and qualified personnel. Information resource is the root. Qualified personnel is the foundation. Technology improves the efficiency. Service builds the library. Academic research prospers the librarianship. And management makes the library strong.