The statistical analysis of influence of summer monsoon,the blocking patterns at high and middle latitudes,the west Pacific subtropical high and cross-equatorial flow on the heavy precipitation in the Yangtze river area was done.The results show that summer monsoon circulation is the result of northward progression of the summer monsoon and the Easterm Asia summer monsoon circulation in weak phase of ITCZ.Summer monsoon circulation and double blocking high with low-cyclone in high middle latitude made the large circulation of the continuous heavy rain gush.They provide south warm-moist current and north cold current separately.The current meets in the Yangtze Area.Rainfall areas were decided by the line of subtropical ridge and western points of the subtropical ridge.The cross-equatorical flow influences the Yangtze basin Area flood disaster mainly.On the one hand,it reinforces the low-level southwest jet,on the other hand,it has a low frequency vibration feature with 4—7 days.Undoubtedly,it provides a useful information for the medium-range forecast.