In this article, the necessity of inter-university cooperation to strengthen research and development (R&D) functions in university libraries in Japan is discussed. As background for the discussion, the author reviews research activities in general in libraries and information science field in Japan, discusses the necessity of R&D on university library activities, and points out the importance of the role of university libraries having R&D departments. An analysis of the R&D activities in two Japanese university libraries and the relating policy documents reveals two major expected roles of R&D departments, namely the R&D itself and the human resource development to be achieved by librarians' participation in R&D activities. Finally, the author proposes ways to meet such expectations in order to focus inter-university cooperation in R&D.