This study presents the case study of a collective action against a proposed industrial waste-water disposal project in the city of Qidong, Jiangsu province in 2012 to explore the role of collective identity in the formation and mobilisation of environmental protests in contemporary China. It is suggested that collective identity articulated through protest is not just a static property of a certain group of people based on their history, culture and locality. Collective identity also works as a flexible framing strategy that can be pragmatically constructed or reconstructed by the discontents, as it interacts with the specific political context in the process of mobilisation.