The paper deals with soil erosion and sediment transportation of the cultivated land in the hilly region of the Loess plateau, employing Caesium-137 as a tracer. The study site is located Zhaoja gully of Zhichang county, Shanxi province. The main results are as follows: 1) The slope distribution characteristic of Caesium-137 has as follows tendency: Caesium-137 content is low at the middle-upper of the slope land, and high at the bottom of the slope land, Caesium-137 content of the upper middle and bottom part of the slope land is 72%, 92% and 157%, respectively of the Caesium-137 average content of the slope land. The Caesium-137 redistribution on the slope land results from runoff erosion and tilling by mankind. The Caesium-137 content exceeds the Caesium-137 regional background value and the Caesium-137 redistribution depth goes beyond the depth of the tilling layer, these demortrate that a part of soil deposited at the bottom of the slope land. 2) The soil erosion modulus of the slope land is between 580t/km~2·a, and 11560t/km~2·a, and the soil erosion differentiation is obvious among different parts of the slope land. The average soil erosion modulus of the slope land is 6230t/km~2·a. 3) The sediment transportation characteristic and sediment delivery ratio of the slope land are discussed, the calculative formula on the sediment delivery ratio of the slope land is established. The average sediment delivery ratio of the slope land is 0.98.