Abstract: In order to study the reproductive status of fishes downstream of the Wudongde dam during its initial reservoir impoundment, and to optimize the implementation of ecological operation of Wudongde Hydropower Station, this study investigated the status of early-stage fish resources in the Wudongdedam section, in the lower reaches of the Jinsha River,during April 21 to June 8, 2021, and March 9 to June 28, 2022. The results showed that at least 3 orders, 7 families and 19 species (genera) of fish spawned and bred in the downstream of Wudongde Dam, including 10 species with drifting eggs and 6 endemic fishes in the upper reaches of the Yangtze River. In 2021 and 2022, the total quantity of fish eggs with drifting eggs was 321.72×104ind and 886.40×104ind, respectively. There were three spawning peaks during the survey period in 2021 and four during the survey period in 2022. Correlation analysis between the reproductive scale of fish with drifting eggs and the hydrological process showed that the reproductive scale of fish with drifting eggs in the Wudongde section was significantly correlated with peak flow (R=0.833, P<0.05), flow growth rate (R=0.810, P<0.05) and the accumulated flow increament (R=0.762, P<0.05).The flood peak can somewhat promote the reproduction of fish with drifting eggs. Compared with the previous survey results, our study indicated that the main species of spawning fish increased and the quantity of fish eggs decreased. Further study is suggested on the reproductive requirements of fish in the lower section of Wudongde dam. It is also encouraged to optimize the operation scheme of the dam to maximize the ecological benefits.