This paper is designed to analyse the ecological discourses of the East-Sea Rim regional studies in Japan.Also, through the analyse the aim and the practices of the ecological discourses of Japan Seaology, this paper has an ultimate purpose of investigating the meaning and limits of Japan Seaology. The research contents are following. First, this paper analyzes about "The New Century of Japan Seaology" series which was published by Japan Seaology Promotion Organization. Secondly, for the analysis of Japan Seaology, I focus on the vision and viewpoint of the East-Sea Rim regional studies in Japan. Third, I examine how an ecological discourse is practiced. Lastly, I critically consider the meaning and limits of ecolization of the East-Sea Rim regional studies in Japan. Through the critical insight of Japan Seaology, henceforth it tried to find the advanced ways in the East-Sea Rim regional studies.