Abstract: The New York Regional Plan Association (RPA) is one of the earliest professional organizations in the world to implement regional planning. Since the 1920s, it has carried out four regional planning programs and conducted a large number of special studies in the New York metropolitan area. The planning has lasted for nearly a century, producing world-class research results. By focusing on the green space planning in the four regional programs, this research makes a study of the planning background, core ideas and planning contents, analyzes and summarizes the evolution characteristics and laws of the regional green space planning in the New York metropolitan area. It is concluded that the homogeneity characteristics are guided by social issues and supported by special researches, as well as the heterogeneity in the view of nature, research vision and planning objectives. On this basis, it puts forward the enlightenment to China’s urban regional green space planning from the perspectives of spatial category, planning content, planning method, and organization mode.