The purpose of this paper is to produce a policy decision making model most appropriate for formulating mental health policy in Korea. This research will also illuminate the legislation process and make accurate predictions about the revision process of the Mental Health Act. Using the Allison Models, we analyzed the legislation process of for the Korean Mental Health Act from the 1980s to 1995, which was largely divided into two periods. We applied the three types of model to each of these two periods. The results of the comparative analysis show that the process of the Mental Health Act enactment can be explained through by each of the three types of Allison models and that there is no dominant model. However, the analysis shows that, compared with the 'Rational Actor' model, the 'Organizational Behavior' model and the 'Governmental Politics' model are better able to explain the decision making process compared to the 'Rational Actor' model.