Based on SVD,the NCEP/NCAR reanalysis data and summer rainfall data over China are used to study the relationship between SLP and rainfall. Results show that the atmospheric circulation anomaly in spring is related to droutght/flood in summer in the middle lower reaches of the Yangtze River.Spring Meridional Pressure Index(I_MP)as well as Zonal Pressure Index(I_ZP) are formed. The results indicate that I_MPandI_ZPhave well correlation with the summer rainfall in the middle lower reaches of the Yangtze River.When I_MPorI_ZP is strong (weak) the rainfall in the area is usually more(less) than the mean value;South China is on the contrary. So I_{MP and IZP are indicative to summer rainfall forecast.}