The article discusses the main trends in the formation and development of a new direction of historical science - historical demography. The purpose of the article is to review scientific papers related to the study of the stated issues. Their general characteristics are given, and key issues are highlighted. The role and significance of socio - historical factors in the demographic process of the first half of the XX century in different regions of the USSR on the example of Kalmykia, Ukraine and Kazakhstan are revealed. A historiographical assessment of losses during the demographic crisis in the USSR in the first half of the 1930s is given.
