Identifying the effects of soil erosion-deposition on soil nutrients and enzyme activities in agricultural watersheds can provide an important scientific basis for soil erosion evaluation. Binzhou River Basin, a typical thin-layer Mollisol area, was selected as the study area, and two representative slopes were selected in the upstream, midstream and downstream of the basin. ¹³⁷Cs tracer technique was used to estimate soil erosion-deposition rates and impacts of soil erosion-deposition on soil nutrients (organic matter, total nitrogen and available phosphorus) and soil enzyme activities (invertase, urease and alkaline phosphatase) at both watershed and sloping scales were analyzed. The results showed as follows: (1) The soil erosion rates were the highest in the upstream of the Binzhou River Basin, which were 1.9 and 11.2 times of those in the midstream and downstream, respectively; at the sloping scale, the soil erosion rates were the highest in the middle slope locations, which were 1.3~2.6 and 2.8~12.2 times of those in the upper and lower slope locations, respectively. (2) At the watershed scale, the spatial distribution of soil organic matter and soil erosion rates showed an opposite trend and the contents of total nitrogen and available phosphorus in the downstream were both greater than those in the midstream; on the sloping scale, the contents of soil organic matter and available phosphorus as well as the activities of soil invertase, urease and alkaline phosphatase in the lower slope locations were all greater than those in the middle slope locations, indicating that soil erosion in farmland declined soil nutrient contents and enzyme activities. (3) The soil deposition rates in the deposition areas of the watershed had significant impacts on the contents of soil organic matter and available phosphorus as well as the activities of soil urease and alkaline phosphatase. (4) The contents of soil organic matter and available phosphorus had significant impacts on the activities of urease and alkaline phosphatase, indicating that the redistribution of soil nutrients caused by soil erosion-deposition was an important reason for the spatial differentiation of soil enzyme activities.