The accuracy of large-scale soil organic carbon estimation depends on data availability from a site based or small-scale measurements. In this study, we estimated soil organic carbon stock (SOCS) and its distribution difference of small catchment in the forest-steppe region. The grid sampling strategy was used to collect samples that covered 3 types of landscape in Ulziit catchment and distance between samples was measured by tape measures in the fieldwork. The average SOCS of Ulziit catchment was 60.8 t ha-1 in 0-30 cm and fluctuation of the distribution was high (CV 62.1%). Then, the result interpreted in mountain north slope, south slope, and valley bottom. SOCS was highest (115.5 t ha-1) in the bottom of the valley and SOCS at the north slope (53.3 t ha-1) and south slope (38.8 t ha-1) were significantly different (P<0.05).
