No.9711 typhoon (WINNIE) is the strongest and the widest influence in recent years in China. The storm surge, caused by the coincidence of the typhoon’s landing with the occurrence of an astronomical surge, resulted in serious damage along the coastal regions of Zhejiang and Jiangsu provinces as well as Shanghai city. After the typhoon’s landing, the centre of the typhoon passed through 5 provinces, while the torrential rain associated with the typhoon system fell in 7 provinces and a city, which made direct ecnomical loss about 25 trillion Yuans. This paper, based on the structures and characteristics of the cloud system on satellite image, classifies the evolusion of this typhoon into 4 stages—the developing stage, the landing stage, the merging stage of typhoon clouds with cold front clouds to the north and the changing stage of typhoon clouds to extra-tropical cyclone clouds. The relationship between the typhoon clouds in different stages and the distribution of torrential rain in space and in time is also discussed.