This paper reports the results of tillage experiments that were set up to investigate the intensity of net soil displacement and the associated tillage erosivity for mouldboard tillage carried out in direction parallel to the contour lines (contour tillage). Tillage was performed with typical set of cultivation for an average farm on soil developed from loess located on a slope with 7.5 to 13.5% decrease. Aluminium cubes of 15 cm edge-length were used as tracers. The studies showed that average translocation of soil along the slope (perpendicular to tillage direction) was 0,35 m and 0,28 m respectively for tillage with downslope and upslope direction of soil overturning. It means that each year about 2,89 Mg per hectare of soil is net displaced in downslope direction per plough operation. The studies indicated that contour moldboard tillage is also an important factor in relief and soil transformation of eroded areas.