Taking the Xilinhe River Basin, a dry cold basin located in the Inner Mongolia of China, as a case, a snowmelt-basedwater balance model (SWBM) was applied to simulate runoff and study climate change impact. The results indicate that SWBMperforms well for monthly runoff simulation, Nash–Sutcliffe efficiency (NSEs) in calibration and verification periods are both over60% while relative error (Res) in both periods are less than 8%. Under global warming, water resources in the Xilinhe River Basinwill present decreasing trend with significant decreasing possibly occurred after 2030