The oxidation of hemoglobin with ascorbic acid gives formation to choleglobin. In these reaction processes, catalase decomposes H(2)O(2) and inhibits choleglobin formation. In this experiment, we compared the degree of hemoglobin oxidation in human acatalasemic blood to that in human hypocatalsemic and normal blood. Results obtained were as follows: Choleheme increased with decrease in protoheme at the initial stage. After a certain time of the reaction, however, the formation of choleheme remained stationary and the formation of choleglobin was lower in the hypocatalasemic blood than the acatalasemic blood and in the case of the normal blood it was the lowest.