Social Network Service is a web-based service that allows the people to construct relationship among users with same interest and supports various activities such as managing personal relations and sharing information or contents. Based on the IS Post-Acceptance model and Success Model, this study examines factors influencing the continuance intention in the SNS. Questionnaires are collected from 275 students who are using the SNS. The results are following: first, the perceived usefulness and satisfaction have positive effect on the continuance intention. Second, the perceived usefulness, confirmation, system quality and information quality have positive effect on the satisfaction. Third, the confirmation has positive effect on the perceived usefulness. Fourth, the system quality and information quality have positive effect on the confirmation. Fifth, the satisfaction is the strongest predictor of the continuance intention and the perceived usefulness is the strongest predictor of the satisfaction.