Abstract:Based on an in-depth analysis of the special situation of mega-projects in China, the dimensions of governance mechanisms of mega-projects are identified, and the nonlinear emergence of governance effect of mega-projects are explored based on system dynamics. The results of the research indicate that the governance mechanism of mega-projects is composed of contract governance, relationship governance, and administrative governance in Chinese context. In the cycle of the implementation of mega-projects, in the early stage, contract governance and administrative governance dominate and promote the development of the project. In the middle and late stages, communication and trust are enhanced among the parties, and the role of relationship governance effectively promotes the improvement of project performance. It surpasses the contract governance and administrative governance and occupies the dominant position, the level of contract governance and administrative governance gradually declined. In each governance mechanism, income distribution, relationship maintenance, and government supervision, especially relationship maintenance, have a relatively large impact on governance performance. The research can provide reference for project participants to improve the governance capacity of mega-projects and achieve project success.