This study was based on the recreation opportunity spectrum (ROS) to establish the classification criterion and framework of local Ecotourism opportunity spectrum (ECOS) of the past and foreign experience. With Sustainable Taiwan, the recreation opportunity spectrum and the feature of ecotourism, this research was establishing ecological, economical and social-cultural goals, 10 evaluative factors and 14 indicators to provide a recreation opportunity spectrum classified basis of ecotourism site. The selected results used by Fuzzy Delphi were 18 evaluative factors and 23 indicators. Six categories of ECOS were classified; they were specialized and middle adventure, specialized, middle and popular ecotourism experience, and cultural scanned.