Abstract Dominance-subordination relationship in semi-domestic reindeer was studied in a group of 16 animals. They were enclosed and for identification they were marked with figures. Observations were made during three periods in autumn and winter of 1962–1963, and studies were also made in free-ranging reindeer. The purpose of the studies was to observe whether the rank order was changed with season, after the shedding of antlers and with other changes in the reindeer and in their environment. During the rutting season the mature bulls were at the top of the dominant list. Within each sex group, age seemed to be an important factor for the rank order, while size and strength were more important between the sex groups, During this time the mature cows were very aggressive to the young bulls. In winter time the reindeer exchanged their feeding craters after a pattern that corresponded to the dominance order in the herd. The mature cows were relatively high-ranked during this time and the calves shared the status of their mothers only when mother and calf were grazing in the same crater. The unantlered bulls were then rather low-ranked, while the bullock in the group remained on a high level in the ranking list. A test was made to discover the influence of antlers upon the hierarchy. Antlers were cut from some animals of the highest status and a drop in the hierarchy after this change was observed. The discontinuity in the ranking lists is discussed as well as some aspects of the biological significance of antlers in reindeer.