Analysis of the climatological features of Jiangnan rainy season precipitation anomalies shows that the month with the most
frequent anomalies of precipitation in Jiangnan is J une and the region is located in the middle of Jiangnan. The SVD analysis points
out that the related sea surface temperature anomaly (SSTA) distributes in the pattern as a“seesaw”. The key region is just located
in the most evident correlation area. The key period of SSTA impact is from May to J uly in the previous year in which SSTA has the
best negative correlation with April to May precipitation in Jiangnan. Under the influence of SSTA“seesaw”pattern the precipitation
anomalies in the following April to J une in East China exhibit opposite phase on both sides of the Yangtze River , the most evident
correlative region is Jiangnan and the middle of which is located in the most obvious area of SSTA impacts.