The purpose of this research is based on the relational benefits perspective to investigate what the key factors the students choose an English cram school are。The Delphi Method and the Analytic Hierarchy Process will be used in this research。 In addition, the literature review and a compilation of expert opinions will be considered while choosing an English cram school by students。 A total of 35 questionnaires are given to students and experts. All these experts have gotten in touch with English supplementary education for more than 5 years and once changed to an English cram school within the 5 years。Questionnaire were sent out by means of purposive sampling on August 4, 2014 and recycled on August 15 of the same year. 32 questionnaires were recycled. After 2 invalid questionnaires were excluded, a total of 30 effective questionnaires were obtained, indicating a valid return rate of 86%。Research results are summarized as follows: Interactive learning website、appointment with peers、professional license、closeness to home, which saves transportation fee、Public praise、free air-conditioning self-study classroom and novel environment.