Abstract The fields of economic development and sustainable development have converged in recent years to form an emerging discipline, which has termed as ‘‘sustainable economic development’. Integration of economy, environment and social performance of the sustainable economic development of a country is very essential for decision-making. Development focus only on economic growth leads to excessive exploitation and endangers natural resources. Ecologically-oriented, sustainable economic development issue has appeared hugely consequences of global degradation, warming and ozone hole in the last third of the twentieth century in all over the world. This thesis focuses on consideration of how donor communities contribute to build sustainable economy in Mongolia. Mongolia made significant steps toward establishing a market economy since 1990s. The challenge over the twenty years, donor communities, such as United Nations Development Program and World Bank, which are playing important role to strengthen and support sustainable economic development in Mongolia. The objective of the research aims to facilitate present and future scenarios considering alternative possible outcomes. This research has intended to donors’ achievement to strengthen sustainable economic development, capacity of national economy and further trend of economic development. The result has displayed large scale projects and development works of donors that are contribute to the sustainability of the country’s development gains by reducing risks and vulnerabilities through enhanced government capacity, and wider partnerships with other sectors and regions. Those have fostered the economic growth and improving the livelihoods of the people. This research contribution is to show importance of sustainable economic development, role of donor communities to build it. Thus it has suggested that government of Mongolia shall identifies the enhance co-operation with donor communities to strengthen sustainability.