In the light of satellite images ,Wuhan digitized radar (WSR-81s) echo data,together with Wuhan auto-raingauges and mesoscale surface observationAL data obtained during July 21-22,1998, the features of the extremely heavy rain occurred in Wuhan city are analyzed.The extremely heavy rain information of mesoscale climatology and satellite images and radar echoes and mesoscale surface system activities in Wuhan city are summarized.