Abstract: As an inevitable product of mobile digital era, mobile library construction is one important index for creating the double first-class universities. Nanjing's universities have their own geographical and specialty features, and their mobile library construction also have a good foundation. Through first investigation on the construction and service status about the mobile library of Nanjing's universities based on regional alliance, their experiences and problems were analyzed. Mobile libraries in Nanjing's universities also had advantages as the sharing model of traditional knowledge. However, there were current bottlenecks for their upgrading from the simple self-service and mutual-help model toward the extent and efficient model. These will provides the upgrading reference of digital library.