Abstract:Based on daily precipitation data of 147 stations in the Yangtze River Basin during the flood season (April to September)for 1960-2005, extreme high precipitation (percentile >95th) and its time gap, days with precipitation <1.27mm/d and its durationwere calculated. Accordingly, spatial distributions and temporal sequences of extreme precipitation events had been analyzed, and theprobability model was established. Research results showed that Sichuan Basin in the upper reaches and southeastern Lake PoyangCatchment in the mid-lower reaches were the high precipitation center of the Yangtze River Basin with centralized extreme event.Total number of days with precipitation <1.27mm/d is more in the mainstream section, Minjiang-Tuojiang Catchment and upperWujiang Catchment than any other area of the Yangtze River Basin. However, due to shorter lasting period of events with < 1.27mm/d,it did not create serious drought situation in theses areas. Whereas, areas in the upper and lower Jinshajiang(upper reaches of theYangtze River) Catchment, Lake Dongting Catchment, southeastern Lake Poyang Catchment, and lower main stream section, weremore likely to be stricken by prolonged events with <1.27mm/d and droughts caused. By applying Weibull model with the method ofmaximum likelihood estimator on the time gap of extreme high precipitation and lasting period of <1.27mm/d, it was proved thatWeibull-Ⅱ can simulate well the probability distribution of timing of extreme precipitation events over the Yangtze River Basin.Changes of Weibull-Ⅱ parameter can reflect well the spatial and temporal variation of timing of extreme precipitation events.