The scale of globally significant events that took place after the Second World War and the victory over fascism, have radically changed the existing world order. These changes have affected not only the political map of the world, but also the general climate of the planet conditioned by the creation and subsequent development of a new universal platform for international cooperation of states - the United Nations, which is not only takes central place in the system of interstate organizations, but also plays an exceptional role in today's international political development. In light of recent events - the aggravation of existing and emerging international conflicts, the threat of international terrorism through Al-Qaeda and Islamic State, the large-scale and flagrant violations of human rights as a result of the activities of the latter - the issue of improvement of the UN and its adapting to severe changes in the international political landscape has become urgent. Additional tasks appear in front of the Organization. Still, in order to be solved, these tasks require some improvements of operational mechanisms and even creation of new ones. The question of reforming the organization has arisen. There have been a discussion on the urgent need for changes within the Organization, but at the beginning of the new millennium, the issue has become particularly relevant. It is obvious that in the current, very complex international environment the main focus of attention in this process should be on reforming the UN Security Council as the principal organ responsible for the maintenance of international peace and security. The article discusses possible models for improving Organization's activities, namely, the expansion of its membership, the problems of working methods, including the use of the institute of veto power, as well as the analysis of the position of member states on the issue of UN Security Council reform. In conclusion, the author highlights the lack of alternative solutions to existing problems through multilateral diplomacy and the special role of the UN in this process as a unique international platform for cooperation of the international community of states.