Based on the observed precipitation,sea surface temperature and NCEP/NCAR reanalysis data from 1979 to 2015,this paper analyzes temporal features of Nanjing summer precipitation.Results indicate that the precipitation has obvious interannual and interdecadal variations,with an overall increasing trend.In 1991,summer precipitation in Nanjing is an extremely positive anomaly,with the anomaly of 343.92 mm,while the precipitation in 1994 is a negative anomaly,with the anomaly of -273.78 mm.There is a significant negative correlation between summer precipitation in Nanjing and sea surface temperature anomaly(SSTA) in the subtropical Northeast Pacific(west coast of California,USA).SSTA in subtropical Northeast Pacific is negative in 1991 and no significant in 1994.The negative SSTA in the subtropical Northeast Pacific in 1991 causes the low-level divergence and high-level convergence over the region,and the low-level convergence and high-level divergence over the tropical Middle East Pacific.Such circulation anomalies cause abnormal upward motion over the Middle East Pacific Ocean.The abnormal upward motion causes sinking motion near the Philippines and inhibits convective activity in the region through zonal vertical circulation,triggers negative EAP/PJ teleconnection wave train,and causes positive precipitation anomalies in the Yangtze River basin,including Nanjing.At the same time,water vapor is transported and converged from Philippines to Nanjing,which is conducive to more precipitation in Nanjing in the summer of 1991.In 1994,there is no significant SSTA in the subtropical Northeast Pacific,and the convective activity near the Philippines is active,which triggers the positive anomalous EAP/PJ teleconnection wave train.Meanwhile,water vapor is transported westward from the Kuroshio extended area through the Japanese islands,and Nanjing region is a water vapor divergence area,which makes the summer precipitation in Nanjing negative anomaly in 1994.