Mobile library can also be called "wireless library" or "mobile library", and its application can be traced back to Japan around 2000. In September 2000, the library of Toyama University in Japan developed the OPAC system of I-type mobile phone bibliography query. This system has just begun to take shape in the mobile phone library. Since then, it has provided online bibliographic inquiry, reminder, reservation, renewal, instant notification and other services for readers of I-MODE mobile phones. With the rapid development of mobile information service in China, the library community soon noticed this new information application. According to the mobile communication technology, the current mobile phone library service includes two aspects: SMS service and WAP service.