Ecosystem services (ESS) are the bases of livelihood in mountains. Among several such services, water and agricultural land are the major ones in Upper Mustang and these ESS services are under threat due to climate change. Water is lifeline and essential for drinking and irrigation. The increasing temperature, and decreasing precipitation and its variability have negatively affected water yield and irrigation. It has directly affected agriculture. In this situation, based on detail field survey, installation and collection of river flow data, and analysis of long term rainfall and precipitation data, this paper discuss the situation of ESS and measures of adaptation that local people have adopted in Upper Mustang, Nepal.