This paper analyzed the trend change, characteristics evolution and hydrological forecasting of the interannual rainfall at the Wuxi station under the influence of warm winters. The results show that under the influence of warm winters, there are drought-moist varying periods of the interannual rainfall at the Wuxi Station, with the characteristics of the hydrological cycle. With this characteristics as the representative in the Taihu Lake region, a rainfall prediction model can be developed, which will break the traditional thinking pattern that there is no regular for interannual rainfall, and improve the prediction efficiency and accuracy.