There have been several complications and problems about marine ranching policy. Regional conflicts have occurred in the process of selecting land for the pasture. And conflict occurred in post-management process. The causes of these conflicts were pointed out to lack of social science research and alternatives. The government-led initiative model, which ignores participation in each sector, has been pointed out as a problem. In order to increase the effectiveness of the marine ranching project, the following points should be considered. First, at the stage of establishing the ocean ranch business plan, social science approach should be considered together with natural science approach. Second, a governance system should be established to enhance the effectiveness of the marine ranch project. The governance system refers to a consultative body in which the central government and local governments, autonomous steering committees, research institutes, local civil society organizations, and participating companies participate. We can improve the efficiency of business by establishing and promoting direction, operation policy, and action plan of sea pasture business centering on governance system. Third, it is necessary to change the management system from the existing administration-led business model to the cooperative governance system - based model. The effectiveness of the marine ranching project can be improved through the governance system.