Until recently, many of the problems on which this monograph is based were the exclusive prerogative of Western researchers. Ideological “taboos” closed the door for Soviet scientists to analyze such issues as demographic catastrophes during the years of Stalinism, the famine of 1932-1933 to 1946-1947 gg., the cost of war. These and many other aspects of the topic are raised on the pages of the monograph. The author, using new and varied materials, most of them previously hidden in the depths of special storage facilities in libraries and archives, makes an attempt to assess the demographic consequences of the functioning of the totalitarian regime and the “thaw” of the 50s. The dynamics of the size and structure of the population of Siberia in the period between the All-Union censuses of 1939 and 1959, mortality trends, type of reproduction, migration processes, etc. are considered.