This article explores the mechanisms of urban self-organization and the role of formal institutions in shaping peri-urban areas. A case study of Gaobeidian, a former rural village that is now part of Beijing, examines the mechanisms of change and the interdependent relations between institutions and bottom-up initiatives that drive peri-urban transformations. The paper presents two main contributions: (1) it identifies the differences between government-controlled planning, shared governance, self-governance and self-organization and how these intertwine in urban transformations; (2) it proposes three distinct roles played by institutions in relation to self-organization: triggering, constraining and enabling. The empirical study of this Chinese case will enrich the current debate on planning for self-organizing cities by revealing the impact of, and the various responses to, self-organization dynamics in a hierarchical institutional environment.