Using information and communication technologies (ICTs), e-participation is a tool that promotes the inclusion of the public in participative and deliberative decision-making processes, thus contributing to a transformation of the interaction between government and citizens in environmental governance and sustainable development. In a number of Chinese cities, citizens increasingly draw on ICTs to promote environmental sustainability and to encourage community-based actions aimed to address various environmental concerns. The potential success of e-participation and the role of ICTs in China has, however, not been well explored. The objective of this study is to understand the role that ICTs can play in promoting public participation about environmental sustainability issues in urban China. Based on an online survey with 630 respondents, the study aims to: (1) analyze what public motivations, perception/attitudes and actions drive environmental e-participation; (2) identify barriers to e-participation, and (3) assess the different applications and functions of ICT for citizen participation in environmental sustainability. The analysis illustrates how ICTs have helped the public to obtain sensitive information about sustainability issues, to mobilize people and to gain media coverage for their actions. The central finding is that new technologies have taken citizen engagement to new heights online. More specifically, the age of ICTs has unleashed a stronger public voice on environmental governance and sustainability issues in urban China, which does not go unnoticed by the Chinese state authorities.