This work presents a use of the ¹³⁷Cs method in the reseach of soil erosion and sedimentation on the agricultural loessial land. There is an urgent need to obtain reliable quantitative data of the soil translocation in agricultural areas and to choose an effective method of soil conservation. After deposition on the land surface, ¹³⁷Cs is rapidly and strongly adsorbed by soil particles. The isotope has been present in the environment since the beginning of nuclear weapon testing and nowadays it is a part of many ecosystems. ¹³⁷Cs is therefore a valuable tracer to study soil erosion and sedimentation rate. Advantages and limitations of the method are discussed in this articles. The activity of the ¹³⁷Cs in soil samples from 4 slopes was measured by means of high-resolution gamma spectrometry and then the ¹³⁷Cs inventories for sampling points were calculated. The ¹³⁷Cs inventories relate to the erosion and deposition rates. The value of soil erosion was calculated by using the proportional model as well as the three mass balance models. The ¹³⁷Cs inventory for studied cultivated field ranges from less than 1.0 up to more than 10.0 kBq m⁻². Differences in ¹³⁷Cs inventory distribution on the terraced and unterraced slopes are clear. The results show that agricultural terraces in the study area were created alter the main period of cesium fallout and that the intensity of soil erosion in the study area appear to be significant.