The article examines the evaluations of the socio-demographic potential of the ethnic regions of the Arctic. The author considers ethnic regions as territories with a high proportion of indigenous small-numbered peoples of the North, who were the first developers of tundra spaces making the areas of their permanent residence and developed there traditional economic activity. In the research, I used the data of regional and municipal statistics, regulatory documents, literary sources as well as Internet resources. On this basis, I have formulated the subject matter, purpose and hypothesis of the research. The main methods are statistical and quantitative analyses of reproductive behavior as well as empirical and balance methods. The retrospective analysis confirmed the hypothesis of the stability of the informal institutions of traditional community and their limited deformation during the pioneering stage of industrial and transport development of the territories of traditional nature use. The results of this study indicate, first of all, the unique character of the studied territories from the point of view of the development of both the traditional nature use sectors and the enterprises of the oil and gas complex. The second major finding is the stability and high role of informal rules in the reproductive behavior of indigenous ethnic groups. This behavior allows extended reproduction of the population living in the regions of traditional economic activities. The research has also shown the special nature and high percentage of mobility of labor for both the aboriginal population (nomads) and the newcomers (shift workers). The obtained results may be used for determining the directions of socio-demographic policy towards the indigenous small-numbered peoples of the North in the areas of their traditional residence. The future research is related to the identification of the consequences of industrial development on the process of reproductive behavior, employment and social organization of the Arctic indigenous population.