Abstract: This article is dedicated to the history of manifestation of collaborationism in the Soviet Union during the Great Patriotic War, as well as the problem of its differentiation from the other forms of cooperation of the Soviet citizens with the German occupants. The author analyzes the normative legal acts, socio-political processes and phenomena of the researched period in order to determine the juridical understanding of the manifestation of collaborationism, as well as the causes and conditions of political, legal, and social character, which contributed into collaboration and establishment of the repressive practice and prosecution of the Soviet citizens who was cooperating with the enemy. Based on the analysis of the historiography of collaborationism in USSR during the period of the Great Patriotic War and its demarcation from the other forms of cooperation of the Soviet citizens with the German occupants, the author determines a number of characteristic features and conditions that promote the formation and realization of the manifestation of collaborationism, as well as substantiates the need for their juridical and moral-ethic differentiation by taking into account the proposed criteria.