This paper integrates relevant index and applies with qualitative and quantitative methods(survey and data analysis) to propose a hypothetical index model for evaluating the service efficiency of digital resources of ancient books,from the perspective of user’s perception.After the hypothetical model was tested and modified by means of EFA(Exploratory Factor Analysis),a final evaluation index model for the service efficiency of digital resources of ancient books was put forward.The weights of the indicators are determined by principle component analysis,showing the degree of response to user expectations in the system.Thus,the relationship between various indicators could be understood and an optimized strategy to improve the service quality of digital ancient books resources is proposed.Service quality,interface design,content construction,system performance as well as retrieval functions are the five key factors affecting the service efficiency.Each of them contains several variables,which basically cover all aspects of the digital service of ancient books.Based on these indicators,this article presents a comprehensive frame for future researches on digital ancient books services.Furthermore,the five key factors shed light on the development trend of the digitization of ancient books,that is,more intelligent,automated,and personalized services.