Deposition of atmospheric N that is depleted in 15N has shown to decrease N isotope ratio (15N/14N,expressed as δ15N) of forest samples such as tree rings, foliage, and total soil-N. However, its effect on δ15N of mineral soil-N which is biologically active N pool has never been tested. In this study, δ15N of mineral N(NH4+ and NO3-) in forest soils from organic and two depths of mineral soil layers (0 to 20 cm and 20 to 40cm depth) of Pinus densiflora stands located at two distinct areas (rural and industrial areas) in southern Korea was analyzed to investigate if there is any difference in δ15N of mineral N between these areas. We also evaluated potential N loss of the study sites using δ15N of mineral N. Across the soil layers, the δ15N of NH4 + ranged from +8.9 to +24.8‰ in the rural area and from +4.4 to +13.8‰ in the industrial area. Soils from organic layer (+4.4‰) and mineral layer between 0 and 20 cm (+13.8‰) of industrial area showed significantly lower δ15N of NH4 + than