Research’s objectives were to determine forest definition, local forest management systems and appropriate REDD models for Thai society. The research used participatory qualitative research methods in 5 research sites. The process comprised of literature review, focus group discussions, field study using community forestry related tools. Appropriate forest definition under REDD scheme in summarized from this study is “areas cover by local tree species more than 2 m. high, with minimum crown cover of 10% and with the size more than 0.31 rai (0.05 ha.). Importantly the areas should incorporate different species of local plants and animals associated into an ecosystem that provides continual products and services to support peoples’ livelihoods and cultures”. Research determined 4 local forest management systems including traditional management system with long term management based on cultural practices, management system where people fought to protect forest resources against external threats, the management system that integrates cultural practices with external knowledge and participatory management in the protected areas. Potential REDD models should relate to these management systems and using REDD+ scheme that consider at least 5 elements; carbon sequestration, biodiversity conservation, cultural protection, sustainable forest management and ecosystem services.