Off-shore wind energy has been drawing interest recently. This research is focusing on the potential analysis of off-shore wind energy surrounding entire Japan coast using GIS Technology. Base on the economy and environment assessment, this research is evaluating the current situation and forecasting on future of wind energy technology in Japan. In order to reduce the green-house gas emission, also due to recent nuclear power problems in Japan, renewable energy (such as wind energy, solar energy, fuel cell) is considered to gradually substitute the primary energy resources (such as coal, oil). In this study, off-shore wind power is the centre of the focus. Based on GIS Technique, off-shore wind turbines in the surrounding of Japanese coast-line are considered. In the study, 2000 kW rated off-shore wind turbines are considered for further installation. As the result of this study, we have determined that 108,067 off-shore wind turbines are expected to be installed in 330 places with annual generation of 180.0 TWh. This is equal to 20% of annual total generated power made by a power companies in Japan in 2010.