On July 22, 2008, a longlasting torrential rainfall envent occurred in Xiangfan ,Hubei Province. Its accumulated rainfall only for 9 hours was 301 mm, as much as 1/3 of the normal yearly rainfall, which was the strongest rainfall according to meteorological records of Xiangfan. The echo structure characteristics, mesoscale system activity and the topographic forcing were analyzed by the Doppler radar data. The results show as follows. （1） There are two echo systems affecting torrential rainfall of Xiangfan, one is the shear linebanded echo which maintains stably in northwestern Hubei, the other is the vortex echo with a spiralechobelt structure. Both together form a vortexband combined echo structure. In the conjunction area, convective echoes emerge and move to the north continually, resulting in the Xiangfan longlasting strong rainfall. （2） The Xiangfan rainstorm event has a close relationship to the established superlowlevel northeasterly jet, and the strong warmmoist southwesterly moving to the north. Because of the Wudang mountain’s barrier located in the west side of Xiangfan, the superLLJ turns to southeast, and forms the mesoscale cyclone convergence with the warmmoist southwesterly nearby the stationary front. The two stranded LLJs play a key role in sustaining convergence near Xiangfan.