The rapid development of information technology and E-commerce proposes new requirements for enterprise's information construction and the suitable evaluation of existing information system (IS) is the important step for that process. In this paper, treating the E-commerce application requirements as the starting points, the author extracts the main factors affecting the IS evaluation from the dimensions of reliability, coordination and integration. Then a multidimensional evaluation model is established using entropy weight method and ideal point method. Finally, the application of the model is discussed.