Abstract: To accurately identify the occurrence and change characteristics of droughts and floods during the soybean growing season in Liaoning Province,daily meteorological data from 44 meteorological stations in Liaoning Province from 1961 to 2020 were used to analyze the development of droughts and floods for soybeans in the region.This analysis was based on the daily-scale Standardized Antecedent Precipitation Evapotranspiration Index (SAPEI).The results show that SAPEI is suitable for identifying abrupt drought-flood events in Liaoning’s soybean-growing areas.During the entire soybean growth period,the number of drought-flood transition events was significantly higher than that of flood-to-drought transition events,and these two types of events have different prone periods and prone regions.Drought-to-flood transitions mainly occurred from the branching stage to the pod-filling stage,accounting for 68%,while flood-drought transitions primarily occurred from the emergence stage to the branching stage,accounting for 66%.In terms of regional distribution,soybean drought-flood disasters in Liaoning Province are mainly concentrated in the northwestern and southern regions.After 2014,the overall risk of drought-flood events for soybeans in Liaoning Province increased.The SAPEI Index can effectively identify the changes of abrupt drought-flood disasters,because it considers the previous farmland soil moisture budget and the water requirement characteristics of soybeans at different growth stages.