The paper offers a sociological evaluation of the October 1917 revolution place in world-historical process as a not bourgeois and not socialist, but the people's democratic revolution of workers and peasants against imperialist wars, capitalist enslavement and the national-colonial oppression. It was the greatest revolution in the history of the liberation, which also carried the beginnings of totalitarianism. October as a sociological phenomenon is incredibly complex, ambivalent and contradictory, because it is constantly opposed by humane, emancipatory beginning and "Jacobin" - ruthless and enslaving one. October 1917 is one of the general tines of world history - its bifurcation point, which opens a new path of social evolution. October is woven of mutually exclusive contradictions, and so today, a hundred years later, it is subject to legitimate criticism. And it is as great a revolution, as the French one.