The weather circulation pattern of the summer tight precipitation period and the main heavy rain course in 1998 were analyzed with the NCAR/NCEP and daily precipitation data from 94 surface stations in Songhuajiang and Nenjiang area.The continuous rainfall can be contributed to the following weather patterns:(1)the steady blocking pattern in the middle and high latitude of Asia,(2) controlled by cold vortex long term,(3)advancing north ward of the subtropical high over the west Pacific and its suitable position,(4)the strong monsoon in midsummer.