Abstract: With the development of mobile communication, the knowledge service of digital library is implemented on mobile terminals, but the existing digital libraries lack of capacity to aware the context such as reader's environment and scenario, so can not offer personalization knowledge recommendation service, which also adapt to the current context and the reader. So a method to measure reader's context sensitivity based on entropy was proposed,and the measure was used to compare two different users based on what the collaborative filtering can be improved. The experiment results show that the improved algorithm can offer mobile digital library a new approach to increase the knowledge recommenlotion accuracy and its context aware ability, then provide reader personalized knowledge resource which also adapt to his current context.

Key words: Mobile digital library, Collaborative filtering, Context, Knowledge recommendation, Eentropy