Abstract: Abstract: University-firm’s co-application patents can reflect the correspondence between scientific achievements from universities and business requirement of enterprises. These patents are analyzed with the method of intuitive and flexible social network graph. The joint application is divided into three dynamic stages from the angle of different geographic region since 1985. And the trends of cooperation center changed from taking Beijing as the only center to diversification including shanghai, Zhejiang and many other provinces. According to the standards for IPC, the distribution network depicts a series of high-profile co-application patents, especially in the high technology areas. And it also reveals those universities represented by Tsinghua University, Peking University and etc have co-applied for most patents since 2000. The comprehensive statistics provide new clues for both of universities and enterprises that search for collaborative partners in some specific technological area. The implications from the study provide the reference to the policy makers and firms in China.

Key words: co-application for patents, social network analysis, cooperative map, technological achievement transfer, technology field