Fusion Experimental Reactors are one of the major steps toward realization of the fusion energy by commercial reactors. Two concepts for such experimental reactors have been developed and designed, one as international cooperation programme, and the other, as domestic programme. The conceptual design of the former experimental reactor named ITER will soon be finished after three years of elaborated efforts. The role and the feature of these reactors are reviewed in developmental point of view of DEMO reactors in the present paper, followed by the presentation of overall output of ITER design and R & D activities in series.
