The influence of soil properties on the diversity of plants and moths (Lepidoptera) were examined in two South Korean high mountain forest localities (Mount Hallasan and Mount Jirisan) and one seashore mountain forest locality (Mount Seungdalsan). Six sites at each locality were included in the study. Soil physical and chemical properties and plant data were obtained from 20×20 m quadrats at every moth sampling site. Moth community data were obtained from the 18 sites. Stepwise regression analysis identified total tree basal area and tree species richness as significant determinants of moth species richness, and plant diversity index as a significant determinant of moth abundance. Total tree basal area was closely related to organic matter (OM), clay content, NaCl concentration, and pH, and plant diversity was closely related to clay content. Nonmetric multidimensional scaling ordination between plant and moth species across 18 sites and 17 soil variables showed that soil fertility factors (OM, total nitrogen content, and cation exchange capacity) were major variables. Our results indicate that soil, plants, and moths communities in temperate forests form a close, interacting network that is primarily affected by the bottom-up impact of soil fertility.