长江上游地区侵蚀泥沙径流观测资料较少,难以确定不同类型土地侵蚀量。本文利用137Cs示踪法测定了长江上游不同土地类型土壤侵蚀量,农耕地土壤侵蚀量介于758～9854t/（km2·a）,非农耕地土壤侵蚀量介于310～4435t/（km2·a）,紫色土裸坡侵蚀量高达12444t/（km2·a）。

The upper Yangtze River Basin with an area of 1×10 6 km 2 is one of the most severely eroded areas in China. Cultivated land on steep slopes is one of the important sources for river sediment in the mountain regions,and soil erosion has significant influences on land degradation and reduction of crop productivity, where absence of direct measurements of the soils erosion rates.The paper reports the results of a preliminary investigation of the potential of using  137Cs measurements on a sloping cultivated land and non cultivated land in the upper Yangtze river.Soil samples were mainly collected from the cultivated slope land and non cultivated land, and the 137Cs reference samples collected from a plain grassland or terraced land where no disturbance sine 1953. The references inventory of 137Cs in sampling sites are between 620.9 Bq/m 2 （Yuanmou county,Yunnan province） and 2 573.2 Bq/m 2（Tianshui city,Ganshu province）.The soil erosion rates of the cultivated land of sampling sites are from 758 t/（km 2·a） to 9 854 t/（km 2·a）. The soil erosion rates of the non(cultivated land are from 310 t/（km 2·a） to 4 435 t/（km 2·a）. Soil erosion rate measurement of the naked purple land is 12 444 t/（km 2·a）.