Abstract: In order to explore the effect of ecological operation of Three Gorges Reservoir on breeding of the Four Major Chinese Carps in Yichang River Section of the Yangtze River, and identify the key ecological and hydrological indexes that affect the natural reproduction of the Four Major Chinese Carps, we investigated the early life resources of the Four Major Chinese Carps in Yichang section of the middle reaches of the Yangtze River, from May to July, 2014-2020. Correlation analysis was made between the Four Major Chinese carps’ spawning and larvae collected and the ecological hydrology index. The results showed that: (1) We estimated that 1.76-86.11×108 ind eggs of the Four Major Chinese Carps drifted through Yichang River Section from 2014 to 2020, which showed an overall increasing change. There were 16 breeding peaks of the Four Major Chinese Carps, mainly from late May to late June. Silver carp (accounting for 61.12%) and Grass carp (accounting for 30.77%) were dominant species in egg composition of the Four Major Chinese Carps, and Bighead carp and Black carp accounted for 3.45% and 4.64% respectively. The spawning time of Grass carp and Silver carp lasted longer, while the spawning time of Black carp and Bighead carp appeared relatively later. (2) Among the 11 ecological operation carried out by the Three Gorges Reservoir from 2014 to 2020, there were 9 corresponding breeding peaks of the Four Major Chinese carps. Except for 2020, the spawning quantity during ecological operation accounted for a large proportion of that during monitoring period，with a range from 20.15% to 78.35%. The daily runoff of the Four Major Chinese Carps’ eggs during the ecological operation period was higher than that during the non-ecological operation period, which proved that the implementation of ecological operation can promote the natural reproduction of the Four Major Chinese Carp. (3) The daily fish egg density was significantly positively related to flow rate changes during the breeding period of the Four Major Chinese Carps in each year(R=0.72~0.97, p<0.05), and the spawning scale during each breeding peak period was significantly positively correlated with the flow rate growth rate (R=0.802,p<0.01), indicating that the flooding process in Yichang River Section can effectively stimulate the natural reproduction activities of the Four Major Chinese Carps. (4) In the Yichang River section, the suitable flow range for the reproduction of the Four Major Chinese Carps is 10 000~25 000 m3/s, and the suitable water temperature range for the reproduction of the Four Major Chinese Carps is 21.0℃~23.8℃. The hydrological conditions of the Yichang River section should meet following conditions will conducive to the breeding activities of the Four Major Chinese Carps in the Yichang River section: the flow range is 10 000~25 000 m³/s, the water temperature range is 21.0℃~23.8℃, the daily average flow increases by more than 2 000 m3/s·d, the water level continues to rise for 4 days.