[Objective] This study tests a new system for building a smart library which provides instant services to the readers based on their locations. [Context] The reader’s needs of service vary with his/her location, and readers at the same location might expect different services. Our new system can predict the real time needs of readers and provide services pro-actively. [Methods] Propose the framework of an active information differential service system based on the location awareness technology. This system can detect readers’ precise locations with the help of WiFi and GPS technology, and then generate personalized service for each individual reader. [Results] After installing the library’s App, the readers can receive different information services at various locations in the library. [Conclusions] Location service helps the library predict readers’ real time needs and improve their user experience.