This paper is an attempt to summarize preliminary findings of a research conducted by the Peacebuilding Policy Research Task Force of HIPEC that aimed at accumulating lessons learned for Japan and beyond from the Disarmament, Demobilization and Reintegration (DDR) in Afghanistan. It seeks to provide an overview of the DDR in Afghanistan, in which Japan involved as a “lead-nation” with the United Nations. A　summary of the outcome of the DDR process in Afghanistan is presented by focusing on its basic characteristics as a political endeavor and an integral part of the security sector reform. The paper also provides a chronological review of the DDR process and the related political development in Afghanistan. Then, it analyzes some critical features of DDR process from four important viewpoints: peace agreement, security sector, governance and long- term social reintegration. By shedding lights on these four focal points, achievements and challenges of the Afghan DDR process will be identified.