The article concerns the reconstructing the features of the formation and evolution of the ethnosocial system, as well as the processes of political genesis of the Altai population at the Xiongnu-Xianbei-Rouran period. The key approach of the research is a comprehensive analysis of materials from excavations of sites of the Bulan-Koby archaeological culture (II century BC – V century AD). More than 800 burials studied in different parts of Altai form the basis of the source base. It has been established that the genesis of the social organization of the population of the region during this period was determined by complex forms of interaction between different clans. The study shows their unequal status at certain stages of the existence of the Bulan-Koby archaeological culture in different regions of Altai, which probably reflects the hierarchy of tribes. The key factor in the political genesis of the region's population was its inclusion in the Xiongnu, Xianbei and Rouran empires. The most probable form of political unification of the Altai nomads in the II century BC – V century AD is a «tribal confederation» without an independent governing center in the person of a common leader and his apparatus.