We analyzed the relation between groundwater nitrate concentration and land use in the Miyakonojo basin. Nitrate concentration was measured in 1,202 wall in February and August from 2007 and 2016. Land use was based on 100m mesh data of National Land Numerical Information in FY 2009 and 2014, and was the ratio of land use type included within a certain distance from the observation point of nitrate concentration. As land use type, we picked up nine items such as rice field, other agricultural land, forest, wasteland, building land, road, railroad, other land and river and lake. As a result, we clarified the tendency of land use type at high and low nitrate concentrations. In addition, we also clarified the land use type that is highly correlated with nitrate concentration. At this time, we examined how to change the correlation coefficient with the ratio of land use type according to the distance from the observation point of nitrate concentration.