Fast Reactor development experiences and status in Japan are summarized. Even though international SFR circumstances were against in 1980s and 1990s, e.g. CRBRP, SNR-300 and Superphenix terminations, we kept on with our R&D activities steadily aiming at positive development targets in Japan. As results of our efforts, it has shown that our commercialized SFR concept, Japan Sodium-cooled Fast Reactor (JSFR) could meet the targets in the Feasibility Study on Commercialized Fast Reactor Cycle Systems (FS) and the Fast Reactor Cycle Technology Development (FaCT) project. Further, Monju has finally achieved restart in May 2010 after having been shut for almost 15 years. A future plan of Monju is to be determined based on a direction of the national nuclear and energy policies that will be established in 2012. The undergoing FaCT project is pursuing commercialization of fast reactor cycle system around 2050 under cooperation of MEXT (Ministry of Education, Culture, Sports, Science and Technology), METI (Ministry of Economy, Trade and Industry), utilities, venders and JAEA (Japan Atomic Energy Agency). As results of the FaCT Phase I, feasibility of the key technologies for JSFR has been evaluated and the project is waiting for launching the phase II due to the Tohoku large earthquake. It is considered that the nuclear development policy might be affected by the Tohoku large Earthquake/Tsunami in Japan. Nevertheless the significance of nuclear energy will not be changed and thus we will focus on the issues learnt from Fukushima accidents and reflect into the improvement of the safety of Monju and the safety design criteria for the next generation Fast Reactor systems.