Abstract: Napahai, located in Jinshajiang Watersheds of northwestern Yunnan Plateau with low latitudes and high elevation, is a unique and seasonal marsh wetland. Developed from limestone in Hengduan Mountain of the upstream of Yangtze River, Napahai bears dissolved snow and controls water level of the down streams. The over years explorations on and cultivation on its marsh soils caused significant ecological and environmental deteriorations. Those deteriorations include wetland shrinking, type of marsh alternation, aridity and sandification, retrogressive ecological succession, mesophytes and xerophytes instead of helophytes, biodiversity decline, soil subsidence, water quality decline and soil enzymes activities changes. Among the analyzed causes of natural water drainage leaching from limestone and human interferences such as over pasture, wetland reclamation and cultivation, the human interferences are the main factor causing the degradation of the ecological environment of Napahai Wetland.

Key words: Jinshajiang Watersheds, northwestern Yunnan Plateau, human activity, environment deterioration, Napahai Wetland