To understand the population characteristics and resource changes of Coreius heterodon in the Yichang section in the middle reaches of the Yangtze River after impoundment of the Three Gorges Reservoir, population parameters and resource status of C. heterodon were analyzed us-ing FISAT Ⅱ software based on the biological data obtained from gillnets conducted in the Yi-chang section during 2003-2005, 2009-2011 and 2017-2021. Results showed that body length range were 118~416 mm, 111~409 mm and 107~380 mm, and weight range were 10~1000 g, 19~889 g and 16~816 g, respectively. Average body length and weight of C. heterodon in the three periods were 230.7±49.8 mm, 217.5±54.3 mm, 267.2±34.1 mm, 195.8±123.6 g, 153.2±118.6 g and 250.3±84.2 g. Growth indices (b) were 3.015 , 3.032 and 2.978, respectively, which be-longed to uniform growth type. The asymptotic length (L∞) of C. heterodon were 535 mm in 2003-2005, 530 mm in 2009-2011 and 500 mm in 2017-2019, respectively, with the growth coef-ficient (k) 0.18, 0.14 and 0.15. According to the length-structured virtual population, annual re-source of C. heterodon were estimated to be 1.10 ? 106, 1.89 ? 106 and 2.10 ? 106 , respectively. After the impoundment of the Three Gorges Reservoir, although the C. heterodon in the Yichang section grew at a uniform rate, and the resource increased significantly, the growth rate slowed down and showed a trend of miniaturization. Results in this paper would provide scientific basis for the protection and utilization of fishery resources in the middle reaches of the Yangtze River after fishing ban.