This research investigated how an innovation system is created, and how technology, value and capability evolve at different stages of an innovation ecosystem. Based on an exploratory and process-oriented case study onof the innovation ecosystem strategy of a nuclear power giant- China General Nuclear Power Group (CGN, formerly known as China Guangdong Nuclear Power Group) for the period 1987-2014, this paper presents an integrative framework to explicate the micro-foundation of the formation mechanism of an innovation ecosystem for complex product system (CoPs) characterized by interdependency and dynamic co-evolution to gain competence. We focus on two research questions on how an innovation system is created and how the elements of technology, value and capability evolve at different stages of the innovation ecosystem. Three ecosystem stages are identified: ecosystem incubation, ecosystem figuration and ecosystem self-renewal. Through the three stages,, through which CGN has been extending its ecosystem gradually from according to levels as core business, to extended network and ecosystem peripherysphere. This study provides theoretical and managerial implicationswill provide valuable experience for building and managing similar innovation ecosystems in developing countries.