One component of the new museology is the ecomuseum, which is intended to preserve cultural/natural heritage and the local landscape in situ, and involves community participation and needs associated with community development. Since the ecomuseum concept originated in Western Europe, ecomuseums must be adapted or localized to various socio-economic environments. In the 2000s, two mining ecomuseums were established in New Taipei City—the Gold Museum and the Houtong Coal Mine Ecological Park. In the early 2010s, two more ecomuseums were established—the Daxi Wood Art Ecomuseum and the Togo Art Museum. More than the mining ecomuseums, the Daxi Wood Art Ecomuseum emphasized community participation and the vision of the Togo Art Museum was led by the community. Based on an analysis of the Houtong Coal Mine Ecological Park, the Daxi Wood Art Ecomuseum and the Togo Art Museum, this study elucidates the various mechanisms of the development of ecomuseums in Taiwan. Ecomuseums should be interconnected with the community and the environment. The three major functions of ecomuseums (community participation, local development, and in-situ preservation) can promote sustainable development. This study uses the “creativity triangle” concept with a three-year cycle of development as an analytical tool. The concept was modified to include three stages of development, which are “estimation”, “preparation”, and “operation”; six steps and 11 tasks are proposed. Despite the unique circumstances of each ecomuseum, this study provides an overview of the development processes and provides a basis for making recommendations for establishing other ecomuseums in Taiwan.