I performed the quantitative estimation of peroxydase in blood of acatalasemia cases, using Bach-Zubkowa's method, and peroxydase reaction of blood were tested according to Mc Junkin's method. Obtained results were as follows: 1) Quantity of peroxydase of blood in acatalasemia were almost equal to normal persons. 2) Peroxydase reaction of blood in acatalasemia cases were almost the same in comparison with that of normal person's blood.