The analysis of the cases concerning international territorial administration involves the results of research of taking over administration over the strategically and internationally important areas in the periods after World War I and II, respectively. All analysed cases among which are the mandates of the League of Nations, non-selfgoverning, strategic and trust territories or generally speaking, 'internationalised territories' in the system of United Nations indicate that international administration of territory is established by the division of power by two or more states in an area or by the transfer of administrative authorities to an international body or the international organisation. As a rule, they are established because the political and social conditions are not fully created as well as because of the unequal power of international legal subjects. The transformation of international territorial administration in the contemporary period results from the transformation of the United Nations collective security system. In critical situations it can serve to achieve political legitimacy and legal and economic subjectivity of the territory.