We evaluated copper content and its distribution in the exchangeable fraction (F1), the reducible fraction (F2), the oxidizable fraction (F3), and the residual fraction (the residues after extraction – F4) extracted with the optimized sequential BCR procedure in the particular horizons of 11 profiles of arable Cambisols and Luvisols of the Siedlce Upland region. In these soils, the varied natural, uncontaminated levels of total copper were determined. For the complete profiles, the average percentage share of copper fractions in the total copper content was arranged in the following decreasing order: F4 > F3 > F2 > F1 (Cambisols) and F4 > F2 > F3 > F1 (Luvisols). In the humus horizons of the tested soils, the highest percentage share of copper was found in F1 and F3 fractions, whereas the enrichment horizons and in the parent material horizons – in the F4 fraction. The highest Cu percentage share in the F2 fraction was measured in the humus horizon of Cambisols and in the enrichment horizons and in the parent material horizons of Luvisols. A statistical analysis revealed the significant impact of selected soil properties (pH, CEC, C_org, clay fraction Ø < 0.002 mm) on copper fractionation in investigated soils. The low total content of copper and low percentage of its bioavailable forms indicated deficit of these elements for plants. Taking into account the normal growth of crops, it is advisable to supplement copper deficiency by fertilization.