Abstract:The relative importance index, mean crowding index, patchiness index, Cassie index and Mrisita index were used to analyze the composition and aggregation characteristics of the dominant species of nekton in Minnan Fishing Ground using the special investigation data of fishery resources in Minnan Fishing Ground in April and October 2016. The results showed that there were 17 dominant species of nektons in Minnan Fishing Ground, including 6 species of fish, 3 species of shrimp, 4 species of crab and 4 species of cephalopod. Polydactylus se-xfilis had the strongest aggregation intensity among fishes, and Loligo beka had the strongest aggregation intensity among cephalopods in spring and autumn. Parapenaeopsis hardwickii had the largest aggregation intensity among shrimps, and Portunus gladiator had the largest aggregation intensity among crabs in spring. Trachypenaeus curvirostris had the largest aggregation intensity among shrimps, and Charybdis japonica had the largest aggregation intensity among crabs in autumn. In spring, Evynnis cardinali, Trachypenaeus curvirostris, Portunus trituberculatus, Loligo beka had the highest mean crowding among fishes, shrimps, crabs and cephalopods, respectively. In autumn, Trichiurus lepturus, Trachypenaeus curvirostris, P. gladiator and Loligo duvaucelii had the highest mean crowding among fishes, shrimps, crabs and cephalopods, respectively. The average crowding of main dominant species of nekton in autumn was higher than that in spring, and the aggregation intensity of shrimp and crab was higher than that of fish and cephalopod in the Minnan Fishing Ground.