Abstract: In this paper,the temporal distributing characteristics of the rainstorm floods in the drainage basin of Yuecheng Reservoir are discussed in two aspects.On the one hand,the temporal distributing characterist ics are identified by counting the number of rainstorm days,the estimated frequencies of the annual maximum typical duration rainfall,the flood peak discharge,and the five-day flood volume in various ten-day according to the observed daily rainfall data and the flood events data. On the other hand,the weather factors of the rainstorm in the drainage basin described in order to validate further the temporal distributing characteristics.The starting and ending time still determined by using the relative coefficients of ten day average rainfall.The results show that there is a distinct pattern of the temporal distributing characteristics in the drainage basin of Yuecheng Reservoir The rainstorms occur frequently with more volume during one period,so there is an obvious main flood season.The flood season in the drainage basin of Yuecheng Reservoir may be partitioned three flood seasons,namely,the former flood season,the main flood season,and the latter flood season.