Interjurisdictional cooperation has emerged as a major recent trend in China in response to challenges from market reforms and globalization. However, given that cities are in fierce competition with one another, interjurisdictional cooperation presents many difficulties for policy making. This paper attempts to examine how cooperative partnerships can be developed, sustained, or even resisted. It uses the Guangzhou–Zhuhai Railway as a case study to explore the institutional configuration of such a practice and to understand how the historical contingencies and path-dependencies in a transitional society interact with intensive bargaining to influence partnership building. It argues that the lack of a formal institutional framework to facilitate horizontal networking forces actors to opt for ad hoc collaborative arrangements. With the objective of making joint projects workable, commitments for cooperation have to be negotiated on a case-by-case basis through extensive bargaining. Although this creates much flexibility in consensus building, it does not guarantee success: success depends on the interplay of inter-ministry politics, interscalar relations, intercity politics and state–market relations. To a certain extent, the Chinese state can go beyond economic logic and shore up its legitimacy by prioritizing development. The post-reform path-dependencies can provide current political leaders with more rather than fewer instruments with which to negotiate interjurisdictional projects, and thus have greater influence over urban and regional economic governance.