With the purpose to determine whether there will be a catalase diminishing action in the blood of acatalasemic patients, at first the catalase quotients of mixed blood consisting of six sets of two normal persons each selected at random have been computed; and then the catalase quotients of the mixture of the blood of the normal and that of acatalasemic patients have been determined. As the result each of these two quotients, namely, that of mixture of the normal and that of mixture the normal and patient's, yielded the value equal to the sum of two respective catalase quotients. Therefore, in the blood of acatalasemic patients there seems to be no catalase diminishing action.