By applying analytic hierarchy process to extend the D&M IS success model, this paper builds a user preference hierarchical model for online consumers to select the most preferred website; this model is mainly constituted by the quality of information, service, system and supplier. Empirical study on agricultural products B2C field has shown that service quality is the most important factor affecting the website selections of online consumers, and e-commerce businesses should make greater efforts to improve the reliability and the rapid responsiveness of service. As supplier quality is highly correlated with user preferences, e-commerce businesses should take a balance strategy to increase product range, improve product quality with lower product price at the same time Information currency is high in the ranking, so e-commerce businesses should pay attention to update information on the website timely.