During the period of almost three decades, from 1912 to 1941, in the area of Old Serbia there were four administrative systems changed. In the article, the author deals with the introduction of Serbian administration after liberation, and the problems that have made this process. Before it was ended, the First World War had broken out. During the occupation, 1915-1918, territory of Old Serbia was divided between Austria-Hungary and Bulgaria, and one part was under German government. After the war, the Kingdom of SCS was created and the issue of administrative divisions came into the center of political conflict between the government and the Croatian block. The laws that were governing the issue of administrative division, adopted in 1922 and on 1929, were in the service of state politics, in order to seduce a powerful centralized system and to eliminate the tradition of historical provinces. During the 1930s, there was a large number of projects created, all about reorganization of the federal government. They all watched Old Serbia like a part of future Serbian federal unit. The outbreak of the Second World War prevented the implementation of these ideas. In a country that was saturated with problems of foreign policy and the struggle of the Croatian issue, the area of Old Serbia was neglected although the problems were never solved.