Accompanying the development of the information systems, there is more and more research focused on the evaluation of information systems. However, the evaluation of the enterprise information systems has always been a thorny problem because of the complexity of the information systems. Through analysis of the existing research achievements both domestic and foreign, we find that some important factors which may influence the results of the evaluation have been generally overlooked, such as the subjectivity of the valuators or the differences between the experts and the users of the system. In this paper, a new model, which takes those overlooked factors into consideration, is proposed. We also adopt different methods to make the evaluation process more objective. Finally, a new evaluation model of information systems will be put forward.