Abstract: In August 2020, a large-scale heavy rainfall occurred in the Jialing River, Minjiang River and Tuojiang River basins in the upper reaches of Changjiang River, and the flood occurred in the main stream and tributaries of the upper reaches of Changjiang River, and the flood control situation was severe. The second highest flood level was recorded in Cuntan station, and the largest flood occurred since the construction of the Three Gorges Reservoir(hereinafter referred to as "20·8" flood). In order to improve the understanding of the rainstorm flood, the characteristics of the “20·8” and “81·7” flood events are compared and analyzed comprehensively. The results showed that:(1) There were some similarities and differences in the characteristics of the two rainstorm floods.(2) The flood-causing rainstorm process lasted generally 6～7 days, and the rainstorm intensity was large and the range was wide. The main rain belt mainly occured in the middle and lower reaches of Jinsha River to Minjiang River, Tuojiang River and Jialingjiang River, and the rainstorm center was relatively concentrated.(3) The corresponding major floods in the upper reaches of Changjiang River were mainly formed by the encounter of incoming water of the Minjiang River, the Tuojiang River and the Jialing River and the baseflow of the main stream.(4) The "81·7" flood process curve was thin, the flood duration was short, the flood peak discharge was larger, and the rare degree of flood peak was higher than that of flood volume. The "20·8" flood was characterized by double flood peak, obesity flood process, higher flood peak water level and being greatly affected by human activities.