An anti-phase relationship of precipitation anomaly between first and second rainy seasons is analyzed based on the daily precipitation data of 134 stations in Guangdong Province and Guangxi Zhuang Autonomous Region (hereinafter Guangdong-Guangxi region) at a total of 2 400 surface meteorological stations of China,the monthly sea surface temperature data from the Hadley Center in the UK,and the monthly NCEP/NCAR reanalysis data from 1961 to 2018.This paper selected those years when the precipitation is above/below-normal in first rainy season (April-June) and below/above-normal in second rainy season (July-September) in the Guangdong-Guangdong region.Results show that in the past 60 years,the anti-phase relationship of precipitation anomaly between first and second rainy seasons in Guangdong-Guangxi region is closely related to sea surface temperature (SST) anomaly in the tropical western Pacific.During the first rainy season,when SST anomalies in the tropical western Pacific are negative,the Rossby wave response of the atmosphere to the negative SST anomalies causes an anomalous anticyclone circulation in the western North Pacific.The water vapor is transported and converged from the tropical western Pacific to Guangdong-Guangxi region.Guangdong-Guangxi region is the wet advection area of water vapor and the anomalous convergence area of wind.The anomalous ascending motion of air is dominant in Guangdong-Guangxi region.This circulation configuration is conducive to the positive precipitation anomaly during the first rainy season.The negative SST anomalies in the tropical western Pacific can persist to the second rainy season.The cold source of the heating could also cause an anomalous anticyclone in the western North Pacific through Mastuno-Gill response,but the location of the anticyclone is more northwestward in the second rainy season than that in the first rainy season.The water vapor anomalies are divergent in Guangdong-Guangxi region.Guangdong-Guangxi region is the dry advection area of water vapor and the anomalous divergence area of wind,and is also controlled by the anomalous descending motion.Above circulation configuration is not conducive to the precipitation in Guangdong-Guangxi region.When SST anomalies in the tropical western Pacific are positive,the above situations are opposite.