This dissertation chiefly examines the difficulties and principles of establishing sustainable ecotourism based on local communities. Furthermore, mainly address management techniques of sustainability in Costa Rica, a country with a growing reputation as an ecotourist destination; meanwhile, throw light upon that effective management and setting up Green Certification Program could improve efficiency. It have been noted that the importance of establishing ecotourism in promoting sustainable maintenances, cultural preservation, and biodiversity conservation within indigenous communities. However, widely management methods to identify the potential and gauge the progress of ecotourism sites have yet to emerge, which is due to there have been few practical assessments of the status of ecotourism at specific locations. In addition, putting ecotourism theory into practice would be much more complicated than originally thought. As far as I am concerned, practical principles combining the most integrated approach would considerably bring mutual benefits between ecotourism and local communities, as appropriate management could help to achieve a balance between conservation and development. With regard to the overall research approach, a case study in Costa Rica will gain prominence in the establishment of sustainable ecotourism since previous research and experience would be highlighted and explored in depth. To some extent, it could be predicted that some gaps between theory and practice of ecotourism would be improved by promoting its sustainability based on communities, resources and economics. As a whole, establishment of benchmark for assessing sustainable ecotourism would be explored as a broader conservation strategy and offers suggestions for further improving the potential of ecotourism.