Abstract: The spatial variability characteristics of soil organic carbon (SOC) and total nitrogen (TN) were studied based on watershed scale, The data were analyzed by the Kriging interpolation method in the SUFER software. The results showed that the means of SOC and TN were 1.60%and 0. 15%, and the variance coefficients were 44. 43%and 30. 73%respectively. Both of them belong to medium spatial variability. SOC and TN presented normal distribution with Kolmogorov-Smirnov test value 0. 123 and 0.04.3. The theoretical semi-variogram models of SOC and TN were spherical and exponential respectively. The Col(Co+C) of SOC and TN were 24.12%and 3.57%respectively. It also indicated that the SOC and TN had strongly spatial self-relativity in this area. The geo-statistics precision of spatial variability of SOC and TN was significant based on watershed scale, with lag O. 500 km and range 7.4-08 3 km. The whole distribution tendency of SOC in this area was higher in the north part than that in the southeast part, but there was the lowest value existing in the middle part just as small block. The TN spatial distribution was similar with the distribution of SOC.