The species composition and community structural diversity of nekton was examined in the autumn at 21 stations in the eastern Bohai Sea (37°40'-38°20'N, 120°00'-121°20'E) using bottom trawl surveys. Analyses were performed using an index of relative importance, ecological diversity indices, multivariate analysis MDS, and CLUSTER using PRIMER 6 software and other methods. We identified 54 nekton species:34 fishes, 17 crustaceans and 3 cephalopods, belonging to 23 families and 33 genera. There were 5 dominant species, with Loliolus spp. being the most dominant. There were also 11 relatively dominant species identified, including Konosirus punctatus, Thrissa kammalensis, Chaeturichthys stigmatias, Oratosquilla oratoria, and Portunus trituberculatus. The relative nekton resources were 28.82 kg/kg² and 5166 ind./h, which had a variable spatial distribution. Much of the resource was centralized, with peak densities congregated around the Long Island Archipelago. Mantissa resources were mainly concentrated around the Long Island Archipelago and in the upper waters of Longkou. Stations SL12, SL14, SL15, SL16, and SL17 had the highest biomass, while stations SL03, SL06, SL07, SL09, SL12, SL15, and SL17 had the highest mantissa. Margalef's species richness index (D), Shannon-Wiener diversity index (H'), and Pielou's evenness index (J') of the community structure ranged from 1.99 to 3.67, 0.89 to 2.28, and 029 to 0.69, respectively. The MDS had a stress level of 0.15, which showed that the community structure of nekton in the eastern Bohai Sea Bay can be divided into three groups:the Long Island Archipelago group (Group A), the Longkou group (Group B), and the Penglai group (Group C). Group A included a single station (SL19), group B included stations SL01, SL02,SL04, SL05, SL08, and SL13, and group C included SL03, SL06, SL07, SL09, SL10, SL11, SL12, SL14, SL15, SL16, SL17, SL18, SL20, and SL21. ANOSIM analysis showed that in the winter, species compositions in the three groups were very significantly different(P<0.01, with very significant differences between any two groups (P<0.01). The typical within-group species and discriminating species between groups had a significant influence on the community structure. The typical within-group species of Group A was Loliolus spp., with a 97.45% cumulative contribution similarity rate. For group C, Loliolus spp., Oratosquilla oratoria, Thrissa kammalensis, Chaeturichthys stigmatias, Apogon lineatus, and Palaemon gravieri combined to create a cumulative contribution similarity rate of 91.46%. For Group B, Loliolus spp., Oratosquilla oratoria, Portunus trituberculatus, Trachysalambria curvirostris and Thrissa kammalensis comprised the cumulative contribution similarity rate of 90.50%. The species discriminating between groups A and C were Loliolus spp., Oratosquilla oratoria, Thrissa kammalensis, Chaeturichthys stigmatias, Apogon lineatus, Palaemon gravieri, Engraulis japonicas, Konosirus punctatus and Alpheus japonicas, whose dissimilarity cumulative contribution rate was 91.26%. For Groups A and B, the dissimilarity was due to Loliolus spp., Oratosquilla oratoria, Portunus trituberculatus, Trachysalambria curvirostris, Thrissa kammalensis, and Apogon lineatus, with a cumulative dissimilarity contribution rate of 53.14%. For Groups B and C, the species contributing to the dissimilarity were Loliolus spp., Oratosquilla oratoria, Portunus trituberculatus, Trachysalambria curvirostris, Thrissa kammalensis, Chaeturichthys stigmatias, Apogon lineatus, Palaemon gravieri, Konosirus punctatus and Alpheus japonicus, with a cumulative dissimilarity contribution rate of 90.64%. The division between groups was relatively stable, as the assemblages conformed to the water environments in the different groups. The resource density and species diversity of Group C maintained a high level, due to restocking, whereas the marine ecological environment of Group A and B was damaged by frequent human activities, causing a reduction in nekton size, and leading to low diversity indices and resource density. This study aims to provide a scientific basis for the rational development and protection of nekton resources in the eastern Bohai Sea.