The article investigates the demographic development of the Siberian indigenous population in the context of the Russian empire and Soviet Union and the web of political and social relationship between the imperial center and the Siberian borderland.. The author criticizes the traditional view, according to which there was a continual decline of indigenous population of Siberia due to the impact of Russian colonialism. The article suggests a more complex explanation of Siberian demographic development, which accounts for various factors, such as assimilation (including the creation of new ethnic groups as a result of interethnic contacts), migration, urbanization, effect of the warfare and epidemic deceases. Examining the processes of assimilation, the author differentiates between assimilation to the Russian population and assimilation to large ethnic indigenous groups, such as the Tatars, Yakuts, and Buryats. Whereas small ethnic groups tended to decline in numbers or became extinct, the Russian, Yakut, Tatar and Buryat population of Siberia continually increased at the expense of small ethnic groups. The author also scrutinizes the impact of the warfare on the size of indigenous population, stating that the decline of the population was due to interethnic combats before the establishment of the imperial rule, conquest by the Russians of certain parts of Siberia (before the 18th century), foreign invasions of the territory of Siberia, and participation of the indigenous ethnic groups in war efforts during the first and second World Wars. Migration, captivity as a result of foreign invasion, exodus as a borderland practice to escape the imperial rule, epidemic deceases and famines also contributed to the fluctuation of the number of indigenous population. Analyzing the effect of imperial rule on indigenous population of Siberia, the author finds that the tribute (iasak) system of taxation and the principle of communal self-government balanced the perils of Russian colonization. This balance in the imperial manner between the center and the periphery changed as a result of processes of modernization and more interventionist policies of the Russian and then Soviet state. The Soviet state eliminated the isolation of indigenous ethnic groups, leading to a greater assimilation to the Soviet (Russian) nation and the decrease of indigenous population as a result of conscription and wars. However, the Soviet regime provided the institutional ground for consolidation of indigenous ethnic groups and modern system of education and social welfare, which contributed to the steady growth of indigenous population of Siberia.