Internal political-territorial structure of the state is being formed independently from its physical-geographic, anthropogeographic, historical ethno-confessional, cultural, communicational, geopolitical, interpolitical external-political and other factors. Its stability, duration and harmony could be achieved by using the complex principle for forming and marking of territorial units. However, their forming sometimes could be the result of administrative, or even ideological - political division of space. This imposed load and historical heritage could be found in Serbia - from the World War II to the modern ideas about the reshaping of Serbian political-territorial organization. Regionalization and constitution of Serbia as a regional state is a good base for eliminating destructive and centrifugal geopolitical processes that lead to the territorial disintegration of state, and at the same time it is a precondition for the decentralization that would provide a more efficient economy for the interest of population. Relatively small number of regions (the most usual is six), with a large area and a large population is not in accord with the needs of modern Serbia. Only organization of Serbia as a regional state with thirteen political-territorial units that, with some exceptions, would have 5.000-10.000 km2 and 500.000-1.000.000 residents, would have reintegrational geopolitical effects. Interregional connections would be intensive and solid, territorial and economic individuality inside the regions couldn't be changed into autarchy, etatism and centralization of newly formed regions. The basic function of suggested regions Bačka, Banat, Srem and Mačva Belgrade, Podunavlje, Western Serbia, Central Serbia, Eastern Serbia, Old Raška, Niš, Southeastern Serbia, Metohija and Kosovo would be to "dismantle" the present anachronic political-territorial division, to reduce and cancel fragmental and barrier effects of internal (provincial) borders and to be in the function of modernization and reintegration of Serbia in the near future.