Abstract: To understand the fish community structure in East Dongting Lake during the mid-term of the Yangtze River's "10-year fishing ban", fish resource surveys were conducted in the breeding period (May) and nursery period (September) of 2025. Fish samples were collected using gillnets, multi-mesh combined gillnets and fyke nets. A total of 7 875 fish individuals were collected, belonging to 57 species, 49 genera, 8 families and 5 orders. Cypriniformes dominated the assemblage, accounting for 70.18% of all species. In terms of ecological traits, non-migratory, benthic and omnivorous fish prevailed. The dominant species included Megalobrama terminalis, Plagiognathops microlepis, Hypophthalmichthys molitrix, Coilia brachygnathus, Pseudobrama simoni and H. nobilis, which collectively contributed 74.67% of the total biomass. The overall Shannon-Wiener diversity index was 2.77, the Margalef richness index was 6.24, and the Simpson diversity index was 0.90. No significant seasonal differences were detected for these indices (p>0.05). The W statistic of ABC curves was positive in both seasons, with the biomass curve consistently lying above the abundance curve, indicating that the fish community was likely under low anthropogenic disturbance and exhibited obvious characteristics of a mature community dominated by large-sized individuals. PCoA and ANOSIM analyses based on Bray-Curtis distance revealed that although trophic composition differed highly significantly between the breeding period and nursery period (p<0.001), no significant seasonal separation was observed for the overall community structure based on species abundance (R=0.037, p=0.500). The results provide baseline information for subsequent dynamic management.