Abstract: The large scale rainstorm flooding induced by the persistent heavy rainfall in summer is the main meteorological disaster in China. Still more efforts are needed to improve the quantitative and refined forecast ability on the characteristic quantity of the persistent heavy rainfall, such as starting and ending time, drop location and the intensity of precipitation. By using daily intensive observed precipitation data and NCEP/NCAR reanalysis data, two persistent heavy rainfalls in Southern China is analyzed and compared to investigate the spatial-temporal evolutioning features and the influencing mechanism of the large scale key influence systems, and atmospheric circulation features of the two processes are summarized as below.During the periods of persistent heavy rainfalls over Southern China in the summer of 2010, the westerly trough over coastland reformed and strengthened frequently and the mid-latitude frontal zone maintained steadily, the low level southwest jet strengthened repeatedly and the strong gradient belt of meridional wind on the left side of the low level southwest jet axis are relatively stable. Meanwhile the latitude location of the subtropical westerly jet, the ridge of South Asia high and the west Pacific subtropical high are also relatively stable in East Asia. Under the joint influences of the large scale key influence systems mentioned above, vapor convergence in the low layer and divergence in the upper layer occurs repeatedly, and the vertical ascending motion strengthens over the heavy rainfall belt, which leads to the formation of the persistent heavy rainfall over Southern China.Before the persistent heavy rainfall in Southern China, the trough in western Siberian keeps reforming and strengthening, shifting to east of Mascarene high and its western high. The subtropical upper westerly jet is also established and maintains in East Asian.The heavy rainfall belt of the persistent heavy rainfall lies in these areas: The strong gradient convergence belt of meridional wind on the left side of the low level southwest jet axis, the strong divergence zone between the south boundary of subtropical upper westerly jet and the ridge axis of South Asia high, the belt of high updraft vertical velocity in the middle layer in East Asian, the south margin of the middle-latitude frontal zone in the middle-upper troposphere, and the north boundary of the west Pacific subtropical high.