Relationship between Western Pacific Subtropical High and Summer Precipitation in Lower-Middle Reaches of Yangtze River

Based on 74 characteristic indexes of circulation,monthly average precipitation data of 160 stations in China during Jan. 1951— Dec. 2003,the relationship between Western Pacific subtropical high and summer precipitation in the middle and lower reaches of Yangtze River was studied by correlation analysis and t-check. The results showed that the summer precipitation in the middle and lower reaches of Yangtze River is negatively correlated with the location of the axis of ridge high respectively. However,it has a significant positive correlation with the size index of the subtropical high separately,and the related coefficient is proven by 0. 05 reliability test.