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Based on the routine weather chart data, the rainfall characteristics and circulation features of a continuous rainfall in the southern Jiangsu Province in early spring of 2009 are analyzed. It is shown that the consecutive rainfall had some unusual characteristics, such as prolonged duration, enormous precipitation, low maximum air temperature, and frequent thunderstorms. During the rainfall event, the upperlevel circulation over Eurasia in the middle or high latitudes came through three stages: Baikal trough type, blocking type, and one trough and one ridge type. Several shortwave troughs split up and moved toward east in midlatitudes of Asia, which ensured the sources of cold air. The Bengal trough was active; the subtropical high over the West Pacific was farther northern than normal; and the water vapor was transported mainly by the outer edge air flow of the subtropical high from the South China Sea and Philippine Sea. As cold and warm air interacted constantly on the lower Yangtze Valley, the consecutive rainfall event of 21 days long formed.