Purpose: Social Network Service (SNS) users feel fatigue in process of using open type of SNS like Facebook and Twitter. Compared to the open SNS，the closed SNS takes an closed form to prevent privacy exposure, and they are more practical and advantageous to form deeper social relationships. This study attempt to examine the effects of the mobile closed SNS characteristics (such as usefulness, playfulness, perceived security, psychological privacy, social influence, and belonging) on the users’ continuous SNS usage intention. Design/methodology/approach: This study used a mixed methodology combining in-depth interviews and empirical validation to investigate the effects of the mobile closed SNS characteristics on the continuous SNS usage intention of users. Findings: Analytical results from a survey of 210 mobile closed SNS users showed that except perceived security, the effects of the five SNS characteristics on continuous SNS usage intention were significant. These findings contribute to improving the quality of mobile closed SNS services and suggesting SNS related marketing strategies.