The companion modeling approach was used to facilitate collective learning process of key stakeholders of a highland watershed in northern Thailand, where a socialagroecosystem is located within the multiple political layers of resource uses and management. After analysis the system, role-playing games (RPG) were conducted with stakeholders using simplified rules and virtual environment. Performing the role allowed players understand consequences of individual role on dynamic processes of the whole system. Information obtained from the games supplemented with interviews mutually improved knowledge of both researcher and stakeholders. The design and results from he games were applied to multi-agents system (MAS) model design using Unified Modeling Language (UML). Cormas platform was used to develop computer MAS model to replicate dynamic and phenomena in the games. The aim is to apply in the field allowing stakeholders to verify, experiment interest scenario that could result in alternative sustainable resource management strategies desirable for all parties.