The 1917's revolution, which led to sovietization and transformation of the universities' structure, was a great trial not only for the Petrograd University, but for a whole system of high education. The data of this article helps to reveal and analyze the reasons and the character of scientists'emigration, and also to construct their "collective portrait". According to this article, the major part of emigrants were scholars of humanities, being at the heyday of their creative abilities. Henceforth most of them managed to continue their professional career in the West countries. Authors consider that the main reasons for the exodus laid in the political and ideological sphere, but not in the academic or material one. They make a presumption relating the consequences of the mass emigration for the Petrograd (Leningrad) University as well as for the science of those countries which gave refuge to the emigrants. Refs 14.