The textbook, based on an analysis of historical and legal sources, examines the historical and legal problems of the collapse of the USSR, determines the legal nature of the 1922 Treaty on the Formation of the USSR and its impact on the events of December 1991; a factual analysis of the main events revealing the essence of the crisis of the federal system of the USSR is carried out; the reasons for the dismantling of Soviet statehood after the political crisis of the summer of 1991 are revealed, as well as events related to the creation of the CIS are analyzed. Each chapter is accompanied by legal and historical sources.