Abstract: It has been shown that large dams and related reservoirs have important impacts on local climate, but the climate effect of cascade hydropower stations is still unclear, especially in dry-hot valley areas.In order to deeply study the impacts of cascade hydropower stations on regional climate, based on the monitoring data of 38 meteorological stations in the basin and surrounding areas of Xiangjiaba-Xiluodu cascade hydropower stations in the lower reaches of Jinsha River from 2005 to 2020,the ANUSPLIN(Australian National University Spline) model was used to simulate the air temperature and precipitation parameters.The PELT(Pruned Exact Linear Time) algorithm, CV(Coefficient of Variation) and Trend methods were further used to explore the spatio-temporal variations of climatic parameters before and after the impoundment.The results show that:(1) the ANUSPLIN model can simulate air temperature and precipitation with high accuracy, with the relative error of 2.26%～10.62% and 9.74%～38.14%,respectively.Moreover, the accuracy for high temperature and dry season is better than low temperature and rainy season.(2) Compared with the pre-impoundment cooling trend in the basin, the cooling rate increased after the impoundment.Specifically, the air temperature increased in winter and summer, and decreased in spring and autumn.In addition, the decreasing rate for annual precipitation also slowed down greatly compared with the pre-impoundment, and the precipitation in summer, autumn and winter all increased significantly.(3) According to the results of mutation test, the air temperature in winter and summer, and the precipitation in spring, summer, autumn and annual precipitation has abrupt changes after the impoundment.(4) After the impoundment, air temperature and precipitation variability was weakened, whereas the stability was increased.Moreover, the closer to the reservoir area, the stronger the stability was.The research results help to deepen the understanding of the climate change effects caused by large-scale cascade hydropower development.