Title of the paper: <b>Proteolytic activities of lysosomal enzymes in dairy cattle, II. Lysosomal enzyme activities and milk performance</b><br> Lysosomal enzymes were gained from plasma and leucocytes using 1011 blood samples of 786 dairy cows. There is a correlation between enzyme activities and milk produetion traits with significant correlation coefficients r<sub>p</sub> = 0,4–0,5 for the daily milk yield at control as well as for the lactation Performance in 305 days during the second third of the first lactation. The level of enzyme activities shows a higher effect on the Performance than the proteolysis. <br><br> No additional gain of information is to be expected from the leucocytes what limits the pallet to the plasma enzymes.