Abstract: Some observational facts of the to rrential rain event occurred in Wuhan and the vicinal area from 20 to 23, July 1998 are analyzed by using conventional and intensive observational data as well as satellite data. The results show that this event was directly caused by a meso-α scale convergence center in the lower troposphere. The meso-α scale system has a cold core structure and a warm core in the upper troposphere. The strong disturbance in the upper troposphere and lower stratosphere and the mesoscale disturbance at surface are related with this torrential rain.