Abstract:Under the background of climate warming, the climate change in Northwest China has become warmer and wetter in recent decades. Based on various meteorological elements such as precipitation, soil moisture, runoff and drought index, this paper further systematically analyzes and studies the evolution of dry and wet characteristics in Northwest China in the past 60 years, and forecasts the future changes in dry and wet characteristics by using the latest multi-model simulation results of the phase 6 of the Coupled Model Intercomparison Project (CMIP6). The results show that the precipitation, soil moisture and runoff in Northwest China in recent 60 years showed a spatial distribution pattern of decreasing from southeast to northwest. The precipitation and runoff in the cold season are significantly lower than that in the warm season, but the differences of soil moisture and drought index in cold and warm seasons are not significant. The annual precipitation, soil moisture and drought index in Northwest China showed significant increasing trends, with the increasing rates of 5.07 mm/10a, 3.89 mm/10a and 0.26 /10a respectively, and especially after 2000, the increasing trends are more obvious. The largest humidification range mainly occurred in the west of Northwest China. The humidification range in the warm season was higher than that in the cold season. However, the runoff showed an obvious downward trend before 2000 and increased significantly after 2000. Under the future climate change scenario, the northwest region shows a trend of humidification in the middle of the 21st century (2031~2060) and the later period (2071~2100), and the humidification degree in the later period of the 21st century is more significant. The humidification under the high emission scenario (SSP5-8.5) is more obvious than that under the medium emission scenario (SSP2-4.5). This study can provide a reference for the impact assessment of climate change in Northwest China.