The paper presents the analysis of the G20 contribution towards the international monetary and financial system reform process,  creation of new institutions,  mechanisms and forms of collective governance and improvement of the existing ones. The author examines the dynamics of collective governance mechanisms development from the first G20 summit inWashingtonin 2008 to the G20 Cannes summit in November 2011. The international institutions (first of all, IMF, World Bank, Financial Stability Board and regional development banks) are undergoing changes in four main spheres: strengthening the system of surveillance over the member-states’ financial and economic policy, strengthening of financial instruments to support the member-states economies, provision of resources to fulfill institutions’ mandates, and  governance reform.

The author asserts that the G20 contribution relevance is underpinned by a combination of three factors: first, the G20 brings together the most significant advanced and emerging economies, second, these countries exert much influence on the international institutions, third, an informal nature of the leaders’ forum allows open discussions of the most challenging pressures and concerns. Though the paper lists some achievements in the international financial institutions reform, much remains to be done, including compliance with the commitments already made. The paper concludes that an effective international institutions system which is capable of completing the reform should include the G20.