In the period between 1945—1976 The League of Communists of Yugoslavia undoubtedly performs the strategic role in socialist revolution. In the total post Second World War period the socialistic socio-economic and political relations are gradually established, self-management, and the material and cultural basis of the socialistic society is built up. The post War period there can be divided into years of typically revolutionary unity and enthusiasm of the masses, which are mainly directed by the League of Communists in new, revolutionary solutions of everyday problems, and those years, when new problems and critical relations between newly grown productive forces and the ones lagging behind, the League of Communists has not been able to provide correct answers. The periodization of this historical period mentioned above could be made on the above mentioned basis.