Social capital refers to the resources embedded in people’s social networks. Since the Internet has launched, the usage of online Social Network Sites (SNSs) has been associated with user’s social capital. Most previous literature was Facebook-based, and only few research paid attention to other types of SNSs, and their influence of users’ social capital. This study investigates how two major used SNSs among Chinese international students in the UK affect their bridging and bonding social capital respectively. In this study, fifty Chinese international students studied at the University of York were recruited and asked to finish computer-based questionnaires for measuring the bridging and bonding social capital and the intensity of SNSs use. The results indicated that both SNSs usages were positively associated with Chinese students’ bridging and bonding social capital. Specifically, the Facebook usage was more associated with the bridging social capital, and the WeChat usage was more associated with the bonding social capital. In conclusion, Chinese international students could obtain different types of social capitals via different types of SNSs respectively.