An analysis of 114 sampling points was conducted in the Shanghuang catchment under different land uses in hilly regions of the Loess plateau. Combined with the geo-statistics method, this study focused on the spatial variation of soil organic carbon (SOC) density with land use and soil depth. The results indicated that the spatial variability of SOC density was low intensity at a depth of 0-10 cm, and middle intensity at 10-30 cm and 30-60 cm. Higher spatial variations were distributed in the natural grassland area to the east and the shrub land in the middle of this small watershed. Soil organic carbon density was significantly different among land uses and soil profile depths; it deceased as soil depth increased. At different depths, the highest SOC density value was in the 10-30 cm layer, and lowest in the 0-10 cm layer. For different land uses, the SOC density showed the following trend: natural grassland > orchard > shrub land > terrace cropland > abandoned farmland > manmade grassland. According to the estimated SOC stock, the total stock of the Shanghuang catchment was 46527.12 t and the carbon storage of shrub land (22052.81 t) and natural grassland (14573.14 t) accounted for 78.72% of the total.