Abstract: It is helpful for libraries to optimize resource allocation and improve the service quality by exploring readers’ behavior. This paper uses 2013—2017 book lending dataset of Fudan University and builds the book Co-borrowing network. Then readers’ borrowing demand is explored by centrality analysis and the formation mechanism of reading community is analyzed from the perspective of agglomerating subgroups. It is found that the demand of readers for books does not follow the law of 2—8, but the long tail theory, making “diversity of books” a principle in books acquisition. The formation of reading community has an effect of time and space accumulation, so online readers clubs may be better than offline ones. 

Key words: Readers’ borrowing behavior, Academic libraries, Literature resources construction, Collection optimization