[Purpose/significance] Active participation of member libraries is essential for the effectiveness of information resource sharing system. Objectively presenting the actual operating status and dynamically revealing the sharing behavior of participating members in the sharing network are important basis for optimizing the sharing system. [Method/process] The study used CALIS Chinese online cataloging data for four years from 2015 to 2018 to build a sharing network with member libraries as nodes, connected by bibliographic data upload and download behaviors. Use social network analysis methods to reveal the actual behaviors of members participating in CALIS co-construction and sharing, the role played by the effect, and the interaction between members. Explore the research path of using social network method to measure the sharing efficiency of information resource sharing system, try to use data-intensive research paradigm to reveal the composition and operation of information resource sharing network.[Result/conclusion] The study found that the sharing behavior of members in the CALIS shared network presents a long-tailed distribution. During the continuous expansion of the member size, the activity of long-tailed member units needs to be further activated; the central pavilion set by CALIS plays the central role and intermediary role in the shared network；when the regional center gradually sinks to the provincial center, is affected by factors such as its authority, region, and strength. There is a certain difference between the central role and intermediary role of member libraries; the differential impact of co-building and sharing activity still exists.