Abstract: Ecosystem service is currently a hot research topic in ecology, especially for critical regions. Located at the southern edge of Qinghai-Tibet Plateau, the Baimaxueshan National Nature Reserve in Yunnan Province is a biodiversity hotspot with special geographical position. In this study, three typical categories of forest ecosystem services (biomass and productivity, water conservation, and nutrient cycling) in the Reserve were evaluated. The forest total biomass was 2215.86×10⁴ t, productivity was 171.84×10⁴ t·a^-1, water-holding capacity was 11964.56×10⁴ m³, and annual absorption of N, P, and K was 26025.94 t, 2638.57 t, and 12016.85 t, respectively, indicating that the forests in Baimaxueshan Nature Reserve had significant ecological benefits, and had importance in maintaining the ecological safety of the local and surrounding areas.