This study focuses on examining the determinants of smartphone-based social network services(SNS) use. That is, the study explores the key factors affecting the use of smartphone-based SNS. People who have been using online-based SNS such as Cyworld and Facebook for years are now using mobile-based SNS such as KakaoStory. Under the situation. the study attempts to draw key determinants of smartphone-based SNS use from the studies of TAM, hedonic information systems, and social perspectives. To test the hypotheses, we conducted partial least squares (PLS) analysis using a total of 233 data collected on the users of smartphone-based SNS including KakaoTalk and KakaoStory. The key findings are as follows : first, it is verified that both ease of use and usefulness, two main factors in TAM, had positive effects on smartphone-based SNS use. Second, for enjoyment and escapism considered as the two main factors of hedonic IS characteristics, only the effect of enjoyment on SNS use was significant. Finally, social ties as a factor of social characteristics had the most significant effect on smartphone-based SNS use. The result implies that smartphone-based SNS can be one of the major means of maintaining existing social ties.