This paper describes the calculation results of the potential quantity of available water resources in each prefecture. At present, there is only the data of the potential quantity of available water resources which is divided into 14 areas in Japan. It is inadequate discussion about the water resources with a viewpoint from prefecture level, so the authors adopt new calculation method. The authors focus on the regional characteristics of potential quantity of available water resources from stochastic method analysis, coefficient of variation and rate of water resources use. Kagawa, Osaka and Saitama have small amount of the potential quantity of available water resources, large coefficient of variation and high rate of water resources use. So the authors estimate that the possibility of water shortage is high in these prefectures.
