The purposes of this study are to illuminate how important are the influences of professional subjects communities in the process of curriculum revisions, and to analyze how the status of school subjects can be sustained through their institutional authorities in the midst of interests and conflicts among professional communities. To accomplish the purposes of the study, how the curriculum has been disputed and negotiated among school subjects is analyzed. For this, the study is intended to analyze the process of the 6th curriculum reform. In relation with this, the activities of each subject community in the concrete situational context are analyzed. As a result, it is concluded that the essences of conflicts among each subject community are whether their subjects are integrated or differentiated ones or not, whether their subjects are compulsory or elective ones or not, and how to secure as many allocation-times in curriculum as possible.