Abstract: In 2022,the Yangtze River Basin experienced a severe drought during the flood season.In order to quantitatively explore the low water regime during flood season in Yangtze River Basin in 2022,based on monthly average flow series of some control stations on Yangtze River main stream, Dongting Lake and Poyang Lake from 1952 to 2022(taking into account the regulation effect of cascade reservoirs),this paper used P-Ⅲ distribution and curve fitting method to analyze the drought return periods of the main control stations, and discussed the uncertainty of drought return periods based on the B-value nomograph method.The inflow regional composition of Yangtze River Basin in August and September 2022 was analyzed by typical year method.The results showed that:(1) In terms of water amount, the water volume from August to October 2022 in Dongting Lake and Poyang Lake was the smallest or the second smallest one during the same period in 71 years, and some return periods exceed 70 years.In August 2022,the inflow in midstream and downstream of Yangtze River was the smallest in the history of same period with return period greater than 70 years.The return period in July to October 2022 was about 30～60 years in the upper reaches of the Yangtze River and Luoshan Station, and the inflow of Hankou and Datong Station was the smallest in the same period.The results of return period analysis indicated that an extreme drought occurred in the Yangtze River Basin in 2022.(2) In terms of the inflow regional composition, the upstream, midstream and downstream of Yangtze River, mainstream and tributaries of Yangtze River all exhibited a severe drought.The proportion of inflow of Luoshan and Hankou Station in that of Datong Station in August and September 2022 was close to or higher than the multi-year average proportion; while the proportion of inflow of Dongting Lake and Poyang Lake in that of Datong Station was significantly smaller in both August and September.From the perspective of inflow regional composition, the drought in the Yangtze River Basin in 2022 was basin-drought.(3) In 2022,the early and low plum rains in the middle and lower reaches of the Yangtze River were one of the main causes of the basin-drought.The impoundment situation of cascade reservoirs in the basin was serious.If the plum rains are forecasted to be early and small, the consecutive summer and autumn droughts are likely to occur.The research results can provide technical support for drought analysis and research in the Yangtze River Basin, strengthening the unified water resources scheduling and management, and effectively improving the ability to cope with drought.