In 1936 the population of the Ainu in Japanese Saghalien numbered 14 33, 712 male and 721 female. Sex age distribution of the population shows as normal with no geographical difference. The type of the population is also progressive. The so called Ainu race according to the most recent census shows 77.62% pure, 18.34% mixed, 3.76% Japanese and 165% Korean. Sex ratio is 98.75%, that is the number of mén is less than that of women, and this ten ency is more noticeabie in old age. The problem of the mixed blood Ainu and the other races is complex. The so called pure blood Ainu may also be some-what mixed, so that the characteristics of racial type will de lost sooner or later.