Abstract:Due to bad climatic conditions and other factors such as overgrazing, building roads, etc. the peat wetland in Gahai degraded seriously, the quality and ecological function of peatlands declines gradually. This study by adopting the method of spatial distribution replacing time-sequence, analyzed the change of soil infiltration and ecological function under four different degradation degrees of the peat wetlands. The results showed that during the first 35 minutes, soil infiltration rate changed differently in different soil layers; soil infiltration rates in 0–10 cm layer and 20–40 cm layer changed stably, and soil infiltration rates were higher in degraded soils than non-degraded one, while soil infiltration rate in 10–20 cm layer changed irregularly. The influences of vegetation degradation on soil infiltration characteristics in different layers within 0–40 cm depth of the peat wetlands were different. In 0–10 cm layer, the initial infiltration rate, the steady infiltration rate, the average infiltration rate, infiltration coefficient and total infiltration of non-degraded peat wetland were different significantly with degraded peat wetlands; in 10–20 cm layer, the steady infiltration rate, the average infiltration rate, infiltration coefficient and total infiltration of non-degraded peat wetland changes in “∽”form; in 0–40 cm layer, the steady infiltration rate, the average infiltration rate, infiltration coefficient and total infiltration declined with the degradation of vegetation. The average infiltration rate had significant positive correlation with soil porosity, but had no significant correlation with soil initial moisture. The protection of alpine peatland ecosystem is essential for the sustainable development of Gahai animal husbandry and the carbon strage of China terrestrial ecosystem.