The target of the investigation was the comparative analysis of conditions determining the dynamics and sustainability of reindeer herding in two Arctic regions – Kola and Yamal peninsulas – based on the authors’ field studies (20102014) and official statistic data. In the 1960s the reindeer stock on Kola and Yamal was commeasurable (74,200 and 103,100 in 1961), however, for the next half a century the difference increased. In 2014 in these regions there were, correspondingly, 54,900 and 293,600 of reindeer. We tried to clear out what it is connected with. Although reindeer husbandries on Kola and Yamal peninsulas have much in common (big herds, long summerwinter migrations from North to South, orientation on meat production), they have also a number of important differences. On Yamal nomadic Nenets herders migrate with their families all year round. Herds are controlled and managed continuously. The majority of reindeer are owned by nomadic families. On Kola peninsula herders’ families live in settlements. T