The purpose of this paper is to determine success factors important to electronic payment system and also to review its environments in order to present development direction of electronic commerce in Korea. A field survey including interviews and questionnaire surveys is made in 12 experts who were identified as having research experiences and/or development experiences of electronic payment systems, 35 merchants who are doing business over the Internet, and 96 netizens who were identified as a consumer group. In this study, we reviewed four dimensions affecting the acceptance of electronic payment systems such as safety, security, convenience, and efficiency. Finally, we suggested a total of 32 factors important to electronic payment systems and classified all factors into four dimensions.