The aim of the present study was evaluation of the influence of sewage sludge from dairy on the enzymatic activity of soil. Soil samples were taken from the experiment estabilished on brown soil. The experiment included the following treatments: 1 – soil + sewage sludge from dairy, 2 – soil + sewage sludge from dairy + farmyard manure (FYM), K – soil control, no sludge. Sewage sludge was applied at the rate 22 t ha-1 yr-1 and FYM at the rate 20 t ha-1 yr-1. In the field experiment the effect of sewage sludge was studied for the activity of the following soil enzymes: dehydrogenases, protease and urease. It was found out that the effect of sewage sludge on the soil enzymatic activity was related to the kind of enzyme under study. Sewage sludge stimulated protease and dehydrogenases activity and inhibited urease activity.