The aim of this paper was to assess differentiation in the total content of Cu, Zn and Mn under the influence of water erosion. The present author investigated parent material, eroded soils and delluvial sediments of a small arable-forest catchment of the moraine zone in West Pomerania. The average content of heavy metals in the parent rock (boulder light loam) were assumed as geochemical backgrounds of Cu, Zn and Mn. It was found out that erosion process caused differentiation in heavy metals. Zinc was the most mobile in this transportation; Mn was not sensitive to it. Delluvial sediments from arable (drainage) depressions had a clearly lower content of Cu and Zn than the parent material. It was also noted that Cu and Zn content in the forest area was lower than in the arable area of a similar relief and soil composition. Mn content was always higher in the arable soils. Soil-forming processes influenced differentiation of heavy metals in the vertical soil profile. The humus and Bt horizons (accumulation of silicate clay) were enriched with heavy metals. A decrease of heavy metal content was noticed in the eluvial horizon (Eet – outwash of silicate clay). The humus horizon of the investigated soil had, a natural (not increased) content of Cu, Zn and Mn.