This article applies neo-functionalist models to explain the process of integration between China and its Special Administrative Region, Hong Kong. Neo-functionalist models are often used to analyse the configuration of regional institutions, in particular European integration. An overview of the model that examines the process mechanisms and factors that have integrative potential can better facilitate our comprehension of the deepening integration of the Chinese and Hong Kong systems, as well as some of the challenges and resistance faced by supporters of integration. This article conveys theoretical and practical implications for China–Hong Kong interactions, the future of the "one country, two systems" principle, and the potential integration of the Greater China region. It also attempts to explain the within-country integration, thereby extending and enriching the neo-functionalist literature.