Soil organic carbon plays important role in soil quality changes and terrestrial carbon cycling. However, the relationships between soil organic carbon distribution and landscape positions were not well understood, which are essential for the precisely predication of the spatial distribution of soil organic carbon and for the rational management of soil organic carbon, as well as for the assessment of the dynamics of soil organic carbon at different landscape positions at different landscape scales. China's Loess Plateau is a major region for agricultural production, and an ecological ecotone in northwest China, which suffers serious land degradation and ecologically economic problems due to the soil erosion in the region. The distribution and cycling of soil organic carbon were related not only with the maintaining and improving of soil quality in the region, but also with the response and adaptation of soil ecosystems to the future global climate change, and thus should be carefully assessed. In this study, we investigated the distribution of soil organic carbon and labile organic carbon at various landforms, that is, plateau land, sloping land, gully bottom and terrace land. We also anlyzed the differences of carbon management index at various landscape positions. The objectives were to establish the relationships between soil organic carbon and the landscape positions in a gully watershed of the Loess Plateau, and to understand how the labile organic carbon and carbon pool management index respond to the landscape positions. The results showed that soil organic carbon and labile organic carbon in the small watershed of the Loess Plateau have variance coefficients ranging from 32% to 70%, indicating medium to high variation. The highest and lowest of total and labile organic carbon were observed in plateau land and gully bottom, respectively. Additionally, total and labile organic carbon decreased with soil depth and the most decrease was tested in high labile organic carbon fraction. The carbon management index in this study can sensitively indicate the response of soil organic carbon to landforms. Among the 3 labile organic carbon fractions, the middle labile organic carbon based carbon management index present the best indication for carbon along soil profile. Our results indicate that the effects of landform on soil organic carbon can partly explain the regional distribution of soil organic carbon in the Loess Plateau.