This study focuses on the evolvement process of organizational model in Chinese megaprojects under the effects of /"Government and Market/" in different periods. Multi-case analysis method was employed to analyze the multi-level organizational evolution and generation mechanism. In addition, relevant data were collected through public publications, network, field studies, and interviews of typical case projects. Megaproject organizations are complexity-adaptive systems, and institutional changes directly influence its evolution. Since the megaprojects have introduced, digested, and absorbed the market mechanism under the transformation of institutional logic, the organization of megaprojects has evolved adaptively into complex multi-level system. This study attempts to propose a conceptual framework of political and market factors affecting the paths of organizational evolution, hopefully providing guidance to Chinese megaproject practices, and laying foundation for the theoretical development.