Abstract: [Objective]In order to study characteristics of warm winter events and the relationship with rainfall in the flood season in Huainan from 1956 to 2017, thus better serve the local agricultural production in winter, disaster prevention and reduction, and prediction of precipitation in the flood season, [Methods] Based on the winter temperature data of Huainan from 1956 to 2017, using the statistical methods such as linear trend analysis to climate diagnositic studies. [Method]According to《GBT_21983—2008_ warm winter grade》, the causes of warm winter climate characteristics and the relationship with rainfall in flood season were analyzed. [Result]The results showed that: the trend of average temperature in winter increased significantly in Huainan from 1956 to 2017, especially more obvious since 1996，and the mutation happened in 1991.The mean maximum and minimum temperature increased, and the mean minimum temperature contributed most to winter warming. The warm winter index showed upward trend, there were 13 warm winter and 7 strong warm winter after the 1990s,but only one weak warm winter before the 1990s. The main factors which result in continuance warm winters, may be the strengthened subtropical high in the western Pacific Ocean, and the outbreak of El Nino Event, and the prevalence of zonal winds and the weaken air at the Asia in winter. [Conclusion] It is found that in the year of strong warm winter or cold winter, the precipitation in the flood season is easy to deviate much, which has some reference value to the forecast of precipitation in the flood season.