A blood group study of the Eskimos living in Anaktuvuk Pass was undertaken. Genealogical relationships and birthplaces were gathered, the gene frequency ratios were computed, and an analysis of the inheritance inside families was made. The frequencies were compared with those of other Eskimo tribes. The presence of blood type B hes been established in the interior Eskimos of Alaska. This is characteristic of the Alaskan Eskimo tribes for whom data now exist. All have varying frequencies of B as compared ;with the Alaskan Indians who either lack B or have an extremely small amount.