Abstract: Analyze the precipitation anomaly of South of China's early flood period, we know the rain peak month of South of China's early flood period has obvious decade change. The change of total precipitation of South of China's early flood period is not obviously. There have many scale oscillations in the precipitation anomaly of South of China's early flood period. The China rain distribution character between more precipitation year and less precipitation year of South of China's early flood period is contrast. And through repeat calculate the correlation between precipitation anomaly of South of China's early flood period and ahead period's (last June-August) SSTA of China's neighboring seas, we find a sensitive sea area which influences the precipitation of South of China's early flood period steadily, the same time we talk about the sensitive time and the relation between it's SSTA、character of circulation departure field of following period and the precipitation anomaly of South of China's early flood period、it's character of circulation departure field, in the end we analyze the relation between SSTA of sensitive sea and SSTA of global sea, then we bring forward a possible mechanism about how the SSTA of China's neighboring seas influence the precipitation anomaly of South of China's early flood period.