[en] In Japan, there are now two power reactors under decommissioning, which are Tokai GCR of The Japan Atomic Power Company and Fugen of Japan Atomic Energy Agency. In main countries such as the US and Germany, there are more than 30 commercial power reactors which have either completed or been undergoing decommissioning safely. Based on these experiences in domestic and foreign countries, preparations for future decommissioning of LWRs in Japan are under way toward establishing socially-reliable and reasonable decommissioning technologies. This paper introduces current preparatory activities for future decommissioning of LWRs in Japan. (author)