ABSTRACT In recent years, government–environmental NGO (ENGO) relations in China have evolved to a point where collaboration is now evident. For example, the government is now purchasing a variety of services from ENGOs and allowing ENGOs to bring environmental lawsuits on behalf of the public interest. This article explains why government–ENGO relations, which were previously characterised by strong government control, have undergone substantial changes recently. By relying on insights from historical institutionalism, this study develops a conceptual framework to explain the evolution of government–ENGO relations since the 1990s. It proposes three closely interrelated stages: environmental authoritarianism (the 1990s), consultative authoritarianism (2000s to 2012) and collaborative regulation (from 2013 onwards). Based on semi-structured interviews and extensive document analysis, this study uses the issue area of water pollution to apply and illustrate the framework. Central to this research is the use of empirical evidence gathered through a case study to establish the usefulness of the conceptual framework in examining the evolving role of ENGOs and the government in China’s environmental policy and governance. Our findings offer a useful perspective to understand the sources and mechanisms of change in social policy in China during the reform era.