Based on monthly runoff data of Yachi River of Guizhou from April 2014 to May 2015,and monthly rainfall data of Guiyang,Xichang,Wenjiang and Chongqing weather stations from January 2007 to November 2015,the influence of temporal-spatial component of regional rainfall on monthly runoff of Yachi River was analyzed by using REOF,multiple linear regression analysis and harmonic analysis.Temporal-spatial change of monthly rainfall around Yachi River mainly contained four kinds of modes.The first mode was northwest-southeast type,and the second mode was south-north type,and the third mode was east-west mode.Temporal components of the three modes were all quasi equilibrium seasonal and interannual changes.Among them,the first and second modes had stable seasonal change,while seasonal change of the third mode was the most unstable,and drought-flood situation of season variation was easy to happen.Seasonal change form of monthly runoff in Yachi River was obviously different from regional monthly rainfall,and it was mainly affected by underlying surface topography and human activity(reservoir and hydropower station),and could not make a natural response to seasonal change of rainfall in time.The third mode of regional monthly rainfall and cycle fitting amount of had insignificant impact on monthly runoff of Yachi River,while the first mode of regional monthly rainfall and cycle fitting amount showed significantly positive correlation with monthly runoff of Yachi River.The second mode of regional monthly rainfall and cycle fitting amount had significantly negative correlation with monthly runoff of Yachi River,and Yachi River had significant water-storage regulation effect on the mode component.Yachi River did not have water-storage regulation effect on flood component of seasonal variation of regional monthly rainfall. Based on monthly runoff data of Yachi River of Guizhou from April 2014 to May 2015, and monthly rainfall data of Guiyang, Xichang, Wenjiang and Chongqing weather stations from January 2007 to November 2015, the influence of temporal-spatial component of regional rainfall on monthly runoff of Yachi River was analyzed by using REOF, multiple linear regression analysis and harmonic analysis. Temporal-spatial change of monthly rainfall around Yachi River mainly contained four kinds of modes.The first mode was northwest-southeast type, and the second mode was south -north type, and the third mode was east-west mode. Temporal components of the three modes were all quasi equilibrium seasonal and interannual changes. Amm them, the first and second modes had stable seasonal change, while seasonal change of the third mode was the most unstable, and drought-flood situation of season variation was easy to happen. Seasonal change form of monthly runoff in Yachi River was obviously different from regional month l y rainfall, and it was mainly affected by underlying surface topography and human activity (reservoir and hydropower station), and could not make a natural response to seasonal change of rainfall in time. third area of ​​regional monthly rainfall and cycle fitting amount of had insignificant impact on monthly runoff of Yachi River, while the first mode of regional monthly rainfall and cycle fitting amount showed significantly positive correlation with monthly runoff of Yachi River. The second mode of regional monthly rainfall and cycle fitting amount had significant negative correlation with monthly runoff of Yachi River, and Yachi River had significant water-storage regulation effect on the mode component. Yachi River did not have water-storage regulation effect on flood component of seasonal variation of regional monthly rainfall.