In Kyoto Basin, high quality and abundant groundwater has been used for drinks, industry, or agriculture. However, in 20th century, there were some problems like the land subsidence because of groundwater exploitation in rapid economic growth. On the other hand, circumstances surrounding groundwater are changing. For example, extreme meteorological phenomenon such as the local heavy rain or the abnormal drought causes more frequent disaster. There are many researches about climate change impact on river flow, but there are a few about impact on the groundwater environment. Therefore, in this study, in order to use groundwater sustainably, we assess global climate change impact on groundwater environment. We use two dimensional saturated groundwater flow model, it is generally used, and we assess climate change impact on groundwater environment quantitatively by ensemble climate experiment.