SNS is the byproduct of the Internet and Web 2.0. SNS has been widely used for communication and entertainment. As a result, many previous studies examined the determinants of SNS usage. While most prior literature pays much research attention on the initial acceptance and use of SNS, the studies about the continued usage of SNS are relatively rare. Therefore, it is necessary to focus on the determinants of users' continued usage, going beyond initial adoption. To investigate factors influencing on continued usage of SNS, this study used ECM model (Expectation-confirmation Model) as a theoretical foundation. Based on ECM model, two critical variables, perceived entertainment and perceived switching costs, were examined. This study collected data by a survey method for an empirical analysis. A total of 271 replies were used for data analysis. While 139 out of 271 replies were collected from Korean users of Facebook, the rest 135 replies were did from Chinese users of RenRen. The collected dataset were analyzed by employing PLS (Partial Least Squares) technique. As results of PLS analysis on the subjects of Korean users, all of the hypotheses were supported. On the subjects of Chinese users, we found that 1) Expectation-Confirmation is positively associated with both perceived usefulness and perceived pleasure, 2) both perceived usefulness and perceived pleasure are positively associated with satisfaction, 3) Satisfaction has a positive impact on continued use intention. However, we found no empirical evidence that perceived pleasure and perceived switching cost are positively associated with continued usage intention.