This chapter studies netizens’ participation in new media and their attitudes towards political issues. New media provides online platforms for viewers to get access to all kinds of materials and express their opinions. The study aims to explore how the online sharing platforms are exploited for public discussion of political issues. It adopts a corpus-assisted approach to investigating viewers’ participation and value positioning towards the Chinese President Xi Jinping’s Speech at UN, 2015. The data are collected from three well-known new media platforms, YouTube, Sohu.com and Ifeng.com, and the analysis of viewers’ attitudes are carried out via the appraisal framework. The analysis shows that new media encourages the public to participate and interact actively on these platforms over political issues. Furthermore, netizens from different regions with different cultural backgrounds have various political value positions towards the same political event. It is argued that a corpus-assisted investigation can better reveal how discourse is shaped by social practice in new media contexts and how the public’s interaction with politics are changed by the discourse in new media context.