Journal of E-Technology Ai Danxiang, Zuo Hui, Yang Jun 8 1 2017 http://www.dline.info/jet/fulltext/v8n1/jetv8n1_3.pdf Recommender systems have been viewed as powerful tools to filter overloaded information in the e-commerce environment. But traditional two-dimensional recommendation methods, which only explore the relevance between customers and products, are not applicable for the recommendation space in C2C (Customer to Customer) e-commerce context that involves three types of entities: buyers, sellers and products. In this paper, we propose a three-dimensional approach to explore the relevance among buyers, sellers and products, and provide personalized “seller and product” recommendations for buyers. Firstly, similarities between sellers are calculated based on seller features. Then the spare data in the threedimensional historical rating set are supplemented and based on which buyer similarities are calculated to find neighbors who have similar product preferences with the target buyer. Finally, a three-dimensional rating prediction model is used to predict the unknown ratings that the buyer may give to candidate “seller and product” combinations. A real data experiment is conducted and the results prove the effectiveness of the proposed approach.