Ecological security is the principal criteria of national security and a fresh water, it’s use are basic component of ecological security. Can be determined briefly that ecosystem services are treasure given by ecosystem to us. There are many kind of services and the main service of them is fresh water ecosystem services. In this paper we tried to show the results if investigation on ecosystem services provided by water. Freshwater ecosystem service gives provisioning, regulatory cultural and supporting services to human well-being. Quality and quantity of water resources play main role to study freshwater ecosystem services and there were indicated the conditions, trends, driving forces in freshwater ecosystem services. In many parts of Tuul river basins, water quality was decreased critically and humans face water shortages for four seasons. Water quality condition, impact of poor water quality on human well-being and economy were analysed. Water shortage depends on naturally and human activities. There were analysed direct and indirect driving forces on water shortage and they negative influences to human well-being. Real evaluation of freshwater ecosystem will give us the true value of water in ecologically and economically aspects and we can see from the trend of ecosystem services valuation that the fresh water ecosystem services will depend on scientific ecological management.
