The Development Trend, Positioning and Services Research of the Library in the Public Service System is an innovative book, which comprehensively and systemically expounds functions and positioning services of librarianship in the context of public service and public cultural service system. Based on the perspective of social public services, it introduces the ecological theory and social network analysis theory to study the internal and external environment of libraries. It has distinctive features on reasonable structure, complete system, illustrations and pictures, empirical analysis, enrich cases and full demonstration.