River discharge has changed significantly in high-latitude permafrost regions due to climate warming, but these changes are still unclear in high-mountain permafrost regions. Long-term discharge data of 8 inland river catchments in the Qilian Mountains were analysed, and increased winter (minimum monthly) discharge, decreased recession coefficient and decreased ratio of maximum monthly to minimum monthly discharge (Q(max)/Q(min)) was detected commonly. This implies that the degradation of mountain permafrost under the warming climate has significantly changed the river discharge of high mountain catchments. Permafrost degradation may influence the relationship between summer precipitation and the following cold-season discharge by promoting liquid water infiltration, increasing the groundwater storage capacity and supporting deep flow paths. However, the role of summer precipitation on cold-season discharge may be affected by different glacier runoff rates (the percentage of glacier runoff contribution to the total annual flow). Under permafrost degradation, summer precipitation will strongly influence the following cold-season discharge in catchments with a low glacier runoff rate (less than 10%) but not the discharge in catchments with a high glacier runoff rate (more than 40%). The results of this study may provide important information for local water resource management and future permafrost hydrological simulation.