The Genji-firefly (Luciola cruciata) is an endemic insect of high conservational interest. We discussed relations between the abundance of the adult L. cruciata and land covers in agricultural landscape in southeastern Tochigi prefecture, Japan. The abundance survey was conducted during the adult period of June at 35 observation points where aquatic and stream edge conditions were mostly homogeneous. Land covers adjoining streams were surveyed by interpretation of aerial photograph and by using GIS. A multiple linear regression analysis and a regression tree analysis were performed for the L. cruciata abundance with surveyed land covers on the bottomland and the valley wall. In the multiple linear regression model obtained, the abundance of the L. cruciata was influenced by the ratio of areas of paddy fields, idle fields and artificial area on the bottomland and woodland on the valley wall. The regression tree obtained suggested that the microhabitat where high rate of areas of paddy fields on the bottomland and woodland on the valley wall, and a low rate of artificial areas on the bottomland had much abundance of the L. cruciata. We concluded that the abundance of the L. cruciata was influenced by land uses around the microhabitat where aquatic and stream edge conditions were mostly homogeneous.