An experiment was carried out in the Yimeng Mountains, a typical earth-rocky mountainous region, in Shandong Province, China. Derived from gneiss and sandstone, the soil therein is loosen in texture and susceptible to soil erosion. Owing to lack of historical data on soil erosion and sediment transferring, it is hard to predict any mediumlong term (50 a) mean soil erosion rate. The method of using ¹³⁷Cs as soil tracer makes it feasible to study soil redistribution on a catchment scale. Moreover, it is reliable and time- and labor- saving. In this experiment this technique was used to study soil erosion and deposition rates in the area. A total of 72 samples were collected and tested for contents of ¹³⁷Cs. Based on the findings, the background value of ¹³⁷Cs of the catchment for the first time defined as 1740 Bq m^{-2 137}Cs. Soil erosion and deposition were calculated by following the soil erosion model constructed by Yang Hao. Results show that the mean soil redistribution rate of uncultivated soil is 2 5305 t km^-2 a^-1 and the cultivated land is 6 952.5 t km^-2 a^-1 on the slope. And the soil erosion and deposition rates are influenced by human cultivated activities and the complex variability of concave and convexity on slopes. The soil in the region is severely eroded, causing decline in water retention capacity of the soil, triggering frequent floods and droughts, and eventually affecting sustainable development of the agriculture and living standard of the people in the region.