Based on the daily precipitation data from 753 stations in China during 1979 and 2010, the spatial scale(23—30°N, 110—120°E) and time range(from pentad 12 to 27) of the Spring Persistent Rains(SPR) are redefined, and the spatial and temporal distribution of SPR are analyzed by EOF(empirical orthogonal function) method.Three main modes, namely, the region consistent type, south-north reverse type and east-west reverse type, are obtained.On this basis, by using the NCEP/NCAR reanalysis dataset, we analyzed the circulation differences between SPR drought and flood years.The results show that in drought years, the southwester over the southeast area of Tibet Plateau strengthens and the western Pacific subtropical high enhances and extends westward, which are conducive to water vapor transport from the south of the plateau and of the subtropical high to the south area of the Yangtze River, and further induce the enhancement of ascending motion and precipitation over the south area of the Yangtze River.Further analysis shows that the heat source intensity over Tibet Plateau in SPR flood years is obviously stronger than that in SPR drought years, which leads to the enhancement of the flow around the southwestern side of the plateau.Therefore, it is conducive to the precipitation in the south area of the Yangtze River.But in drought years, the situation is just the opposite.In addition, by comparing the zonal land-sea thermal differences between East Asia continent and the Western Pacific, it is found that the inversion between cold and heat source occurs at about the 11th pentad in flood years.However, the atmospheric source reverses at the 16th pentad in drought years.The intensity of heat source during SPR over the south area of the Yangtze River in flood years is also stronger than that in drought years, which further explains that the inversion and enhancement of the zonal land-sea thermal contrast play an important role in producing the SPR, and it is also an important indicator in determining the monsoon precipitation characteristics of the SPR.