The blood samples of 17 bison (7 cows, a heifer, a young bull and 8 calves) formed the basis for conducting analyses of blood plasma. The measurements were carried out by using ionoselective electrodes aided by a Hitachi 917 biochemical analyser. An interpretation of the results was possible due to comparison with the results of similar analyses completed in the United States. Many differences in blood chemistry values in bison bred at Kurozweki were found in comparison to bison from the US.