This paper presents dependences between the contents of Cu and Pb, and the enzymatic activity of dehydrogenases, acid phosphatase, urease and protease. Studies were carried out in soil samples taken from upper horizons of black earth and grey-brown podsolic soils in the neighbourhood of the Legnica Copper Works. The analyzed soils showed silt texture (SiC) and a differentiated content of organic matter. Upper humus horizons were characterized by high contamination by Cu and Pb, but their amounts decreased with an increasesd distance from the emission source. Significant amounts of the mentioned mineral xenobiotics caused a distinct decrease of biological life activity in the analyzed soils.