AbstractDominance relations among adult females in the Katsuyama group of Japanese monkeys (Macaca fuscata) were analyzed. Dominance relations among female relatives of 6 or more years of age corresponded almost exactly to those predicted by Kawamura's principles [Primates, 1:149–156, 1958] in the four highest‐ranking kin‐groups. According to these principles, 1) a mother is dominant to her daughter and 2) among sisters, the younger is dominant to the older. However, 9 of the remaining 11 middle‐and low‐ranking kin‐groups included dyads in which dominance relations did not correspond to those expected from Kawamura's principles. Within the dominance rank order, of all 74 adult females of 6 or more years of age, individuals of the high‐ranking kin‐groups always ranked adjacent to members of their own kin‐group, while individuals in middle‐ and low‐ranking kin‐groups tended to be ranked independently of members of their own kin‐groups. These results indicate that, since females of a high‐ranking kin‐group form a cohesive matrilineal unit, it may be very difficult for females of other kin‐groups to break into the dominance rank order that exists among females of the high‐ranking k