Abstract: To analyze the evolution trend of droughts for many years and predict future droughts, we used the Standardized Precipitation Evapotranspiration Index（SPEI）, Mann-Kendall test, Mann Whitney Pettitt mutation test, nonparametric statistical test, and rescaled range R/S analysis method based on daily meteorological observation data from 13 national meteorological stations around the Xilin River Basin. The results indicated that sudden changes in the drought pattern began in the 1990s. In the past 60 years, SPEI has shown a significant decrease trend, and the decreasing trend in the upstream is smaller than that in the middle and lower reaches. The middle and lower reaches are drought-prone, and the northwest end of the downstream is a dangerous area where drought exists. Although droughts are mitigated in the future, they may continue to increase in winters. Therefore, drought monitoring needs to be strengthened.

Key words: SPEI, SPI, drought changes, Mann-Kendall, Xilin River Basin