local community, and respect for local culture. Ecotourism development will inevitably have an impact on community life, bringing significant change to ecological, economic, social and cultural aspects of the local community. This research describes community participation and stakeholder intervention in sustainable ecotourism development on Lawu mountainside. The research location was chosen purposively based on previous observations through the internet, a literature study, and a research survey, and consideration that community based sustainable ecotourism development is experiencing rapid progress on Lawu Mountainside in Karanganyar Regency, Central Java, and Magetan Regency, East Java. The research method is descriptive qualitative with a phenomenological approach. The data analysis was carried out with an interactive analysis. The results show that ecotourism development on Lawu mountainside focuses on community participation, where the community has local knowledge about nature and local culture that has potential to become a selling point as a tourist attraction. Stakeholder intervention in ecotourism development is proven to promote values of social capital, develop the creative economy in the local community, provide opportunities for the local people to become the main actors in ecotourism activities to build working relations, and improve the capacity of local institutions to play a role as an agent of change.