Along with the rapid development of digital library, digital library of the third generation, taking the main characteristics of the personalized service, has already become the mainstream today. This article first analyzes the concept and characteristics of digital library, then elaborates the inevitability of personalized service as well as the necessity of its development and based on the Propose of establishing interested knowledge-base, enumerates several ways of personalized service, at last according to individualized service, this paper proposes the model of "learningoriented individual digital library" and prospects the trends of digital library.