Abstract: Government agencies are now leveraging social media to better disseminate information to their citizens. However, there is little empirical research on what factors may drive citizens to participate in government WeChat proactively. In view of this, this study, drawing on the Delone and McLean information systems success model, intends to propose a model to identify the antecedents driving WeChat subscription account participation. The research model is validated through a panel dataset collected from 323 WeChat subscription accounts of 21 cities (autonomous prefectures) in Sichuan Province. The results show that WeChat subscription accounts' system quality, information quality, and services quality are positively associated with the WeChat subscription account participation. The results can not only enrich our understanding on government social media participation behavior, but also help government agencies enact social media development strategies to increase citizen participation and harness the power of social media.