The emergence of SNS has changed the ways of people’s socializing. This paper took SNS users’ sense of belonging as the objects of the research, and it assumed through literature search that SNS satisfaction and trust were the influence factors of sense of belonging among SNS users. Before we carried out this research with the data collected from America, we had already done once in China. We built a theoretical model by combining with influence factors including QOS, member relations, interaction, participation and system guarantee to reveal the impact mechanism of SNS users’ sense of belonging. Then we verified and adjusted the model with the help of VisualPLS, and proved the hypothesis to be true in both China and America.