Compared with smart city in the USA and Europe, the Japanese smart cities suggest a wider range of concepts that cover from urban development, transportation infrastructure, energy supply infrastructure, city lifeline and information infrastructure. In the energy sector, it suggests great concern on the regional cooperative energy using in district scale with introduction of distributed energy resources. Furthermore, compared with the USA and Europe, the Japanese smart city model not only focus on the energy saving and low carbon effects but also the disaster resistance as well. In that case, most of the Japanese smart cities consist of two models, the normal-time model and the emergency-time model under the disaster. All the concepts and features of Japanese smart city are embodied in the trial smart communities, covering from the building level to the district level. In the building level, it promotes the renewable energy resource and EV using for housing, and ZEB for office and commercial. In the district level, it conducts a two-way energy supply system between the district energy system and the grid