This paper purports to outline the prospects and issues in systemizing ecological defense planning and to assess the progress in the ROK. While the defense sectors in the United States and a number of European states have taken steps toward systemizing ecological measures in recent years, progress in the ROK has been slow. Problems point to not only technical challenges in systemizing ecological measures, but also to the lack of political and bureaucratic facilitation. To examine the problem in question, the paper is divided into four sections. First, the paper will outline the environmental impact of military institutions and their actions. Second, the progress in systemizing ecological measures in the defense sector will be examined. Third, problems in Korea's handling of environmental issues relating to the defense sector will be assessed. Then, in the fourth section, the paper will outline the key steps the ROK must take in systemizing ecological defense planning. The paper concludes that further efforts are needed in conceptualizing and systemizing ecological defense planning to not only shape new norms in the defense sector and their activities, but also to comprehensively address both traditional and non‐traditional security concerns in the region.