The peculiality of blood typing is a constant physical phenomena to every person, so I think there is any relation between various kinds of eye diseases and his blood typing. Therefore I have reserched this relation. The. items I have studied are as follows. 1) That I have examined the blood typing of 1.200 cases of eye diseases, and also the state of the distribution of blood typing together with its effects on the erros of reflection and the diseases of eyes of 300 boys and girls. 2) To have examined the relation of the iso- and hetero-haemagglutination about normal persons and rabbits. 3) To have measured the iso haemagglutination value of 75 persons including 24 chief eye diseases, and examined if there is any difference of its value. The results I have got can be summed up as follows. 1) The distribution of blood typing in the case of trachoma increases a little in A typing, and most in AB typing. In the latter the rate of infection is highest, but it seems we do not suffer great injury. In B or O typing the rate of infection decreases a little, but in O typing we suffer serious complications of trachoma, and it seems we have general tendency of decline the resistance of trachoma. 2) In myope, A. B. O. each typing decreases a little, but AB typing increases. High degree of its refection has a tendency to increases in O typing, mean degree in B typing, and low degree in AB typing. The distribution of blood typing in hyperope is similar to that of the case of myope. In astigmatic person A and AB typing increases a little, and O typing decreases slightly. 3) The other various diseases of eyes have some exceptions, but on the whole A typing decreases a little and AB typing increases. 4) The cases of trachoma in the primary school have a general tendency increasing A typing, and myope increasing A typing and decreasing O typing. 5) The value of iso-haemagglutinin of normal persons is generally the same degree, and almost between 256 and 512. 6) The normal rabbits lack the iso-haemagglutinin. 7) The value of heterohaemagglutinin of serum of normal person to the blood corpuscle of normal rabbits is rather in high degree, and a little higher than the value of the isoagglutinin of normal persons. 8) The value of heterohaemagglutinin of serum of normal rabbits to the blood corpuscle of normal persons is almost from 2 to 64, and the state of agglutination to human blood corpuscle of O typing differs from the other 3 typing. 9) The value of haemagglutinin of various cases of eye diseases generally decreases rather than the healthy one, but in some cases we find so high degrees of its value that we cannot find in the case of normal person. The mutual value of haemagglutinin of each eye-diseases is complicated and so it is difficalt to give even any simple meaning between them. But the value of haem agglutinin increases from the old to young, and in the female than in the male.