Abstract: The object of the research is the referendum about participation in the European Union that was held in the Great Britain. The subject of the research is the main economic consequences of Brexit including domestic and foreign policy of the European Union and Great Britain. Within the framework of this research, Brexit is viewed as a factor that reflects the global process of transfer to a new geopolitical reality. The author of the article pays special attention to European scientific cooperation and major international research projects. The author demonstrates that the scientific sphere gradually loses its financial independence and faces a growing migration of science and research specialists. In the course of this research the author has used historical, logical, statistical and prognostic methods that allowed to achieve the targets of the research. The author concludes that Brexit may cause recession for the Great Britain including the fall in British currency rates, inflation growth, poorer investment conditions, reduced volumes of the external trade with the EU, etc., up to a real threat of the Kingdom collapse. At the same time, the EU experiences the influence of crucial geopolitical, economic and military factors which, in its turn, may significantly weaken the role of the EU on the global arena.