In the context of China’s new law against domestic violence, proposed by the State Council in November 2014 and passed in July 2015, this article examines online engagement by Chinese citizens leading up to the legislative revision, and examines the Sina Weibo microblog activities of one influential organisation, nǚquán zhī shēng (Feminist Voice). I ask how a Chinese Civil Society Organisation (CSO) uses online media to open public discourse on, and in some cases challenge, formal and informal institutions around a normatively marginalised issue, the case of domestic violence. Drawing on and synthesising literature on domestic violence, civil society and online communications in China, this study provides a timely contribution given the relative limitedness of up-to-date data, after the huge wave of publications following the 1995 Beijing conference. Findings are based on content analysis of the Feminist Voice microblog during 2012. While Chinese CSOs are often dismissed as non-confrontational and therefore ineffective change agents, Feminist Voice does challenge status quo marginalisation of domestic violence in the public sphere and facilitate discussion around formal and informal institutional reform, thereby influencing social attitudes and potentially also policy and law making.