The Management of Dualism Leadership in Sekolah Nusa Alam a Cooperation Education Unit based School in Lombok, Indonesia

. The aim of this research is limited to several factors that might cause “the tragedy of the commons” between a principal and a Kepala Sekolah. These factors are 1) cultural background, 2) differences in leadership models, and 3) differences in organizational behaviour. The research was conducted using a qualitative method with a single case study research design. The research was undertaken in one location, Sekolah Nusa Alam in Lombok. Data research techniques and procedures were unobstructed observation, semi-structured interviews, and data-checking processes. Interviews were conducted with six people using the purposive sampling method. The data analysis procedure was carried out by collecting the data, reducing the data, presenting the data, and concluding the data. The research showed that the cultural background, leadership model and organizational behaviour could trigger the ‘tragedy of the commons’ between the principal and Kepala Sekolah in Sekolah Nusa Alam. It is concluded that this happens because there is no or no misunderstanding in terms of communication, the application of leadership models and different organizational behaviours that lead to the misunderstanding in the collaboration betwe en the two that trigger “the tragedy of the commons”.