Abstract: Poyang Lake is a typical alternately filled lake that connects to the Yangtze River. Flooding characteristics of the lake are obvious with lake water level and inundation area vary significantly in season and space, showing highly nonlinearity. Based on the observed water levels and reconstructed high spatial-temporal resolution inundation dataset of the Poyang Lake according to multi-source remote sensing data from 2000 to 2018 by adopting the ESTARFM model (Enhanced Spatial and Temporal Adaptive reflection fusion model), this study explored the formation mechanism and evolution of stage-area hysteretic relationships in the lake. The results show that the hysteresis of stage-area varied significantly across the lake. Both clockwise and counterclockwise hysteretic functions can be observed in the Poyang Lake. The formation mechanism of the two hysteretic functions is mainly attributes to the different flooding characteristics of river and lake facies and the differences of converge and drainage processes in the upstream and downstream of Poyang Lake-floodplain system. Duchang station in the middle of the lake shows the smallest stage-area hysteresis across the whole Poyang Lake, while the Kangshan station at the southernmost of the lake shows the largest stage-area hysteresis. Seasonal lakes that widely exist in the floodplain settings of Poyang Lake have important impact on increasing the hysteresis of upstream stations and reducing the hysteresis of downstream stations in the lake. In recent years, the stage-area hysteresis of different stations in the Poyang Lake have changed significantly due to the alteration of the lake outflow capacity and catchment inflow caused by regional climate change, sand mining activities in the lake and the operation of Three Gorges Project. Before and after the multi-stage experimental impoundment of the Three Gorges project, the hysteresis of stage-area in the northern Lake area represented by Hukou, Xingzi and Duchang stations experienced a process of first increasing and then decreasing during the periods of 2000-2003, 2004-2009 and 2010-2018, respectively, while opposite process was observed in the southern lake area represented by Tangyin and Kangshan stations.