The persecution of foreigners in the USSR attracts the attention of Russian historians most often as a prologue or component of the Great Terror. At the same time, it is important to understand that the legal mechanism that made it possible to arrest foreigners as early as the second half. 1920s took shape gradually and generally took place long before 1937 - 1938. The methodological basis of the research was made up of historical-genetic and historical-comparative methods, and also practiced the use of the retrospective method.