Soil losses provided by 210Pbex measurements in the sites ranged between 0.03 and 0.28 cm per year. The annual rate of net soil loss estimated by 210Pbex method was from 342 t km-2 y-1 to 3806 t km-2 y-1. The mean depth and rate of soil erosion were 0.18 cm yr-1 and 2297 t km-2 y-1 in the contouring corn field. On the basis of soil loss rate by 210Pbex and sites condition, the soil loss of 6200 t km-2 y-1 from up-and-down slope was simulated by RUSLE2. It is assumed that contour practice and up-and-down cultivation are on the same field. All factors are the same but ridges direction of farming. The soil losses from up-and-down and contour farming in the same field were simulated, and the sediment delivery was 6200 t km-2 y-1 and 2100 t km-2 y-1, respectively. Contouring tillage reduced average soil loss 63% from up-and-down tillage at the field level. This result is similar to the monitoring data on the key small watershed plots [12].