根据1998-2001年长江口近海4个航次鱼类拖网调查数据，运用群落生态学分类和排序方法，分析了长江口近海鱼类群聚结构特征及其与环境因子的关系。筛选后的64个站次的48种长江口近海鱼类分属10目28科，鲈形目种类最多，灯笼鱼目，鲈形目和鲱形目鱼类丰度共占总丰度的 99.81% 。龙头鱼、七星底灯鱼和黄鲫为秋季优势种，银鲳和皮氏叫姑鱼为春季优势种。相同季节年度间的鱼类群聚差异不显著，春季(5月)和秋季(11月)鱼类群聚有明显的季节分化。CCA分析显示：1998-2001年长江口近海鱼类群聚的主要影响因素是水深、底层温度、底层溶解氧、表层总磷和pH值。

Spatial and temporal variation of fish assemblage structure in the adjacent sea area of the Yangtze River estuary and its relationship with environmental factors were studied based on fish abundance data sampled from 1998 to 2001. Multivariate methods were adopted including both hierarchical classification and constrained ordination. Rare species were excluded, the remaining 48 species fishes belong to 10 orders, 28 families. Among them, the species number of Perciformes was highest, and three most abundant orders contributed 99.81% of the total count: Myctophiformes, Perciformes and Clupeiformes. Dominant species were different between the seasons: Harpodon nehereus, Benthosema pterotum and Setipinna taty were dominant species in autumn; while Pampus argenteus and Johnius belengeri in spring. The interannual differences during same season were not significant, but the seasonal differentiation was found between autumn and spring. The canonical correspondence analysis(CCA) show that fishes were separated into four ecological assemblages: hypsithermal-saline, hypsithermal-brackish, hypothermal-brackish, and hypothermal-saline group. The nearshore area represented an abundance peak of fish community in the adjacent sea of the Yangtze River estuary. Significant dissimilarities of assemblage structure and habitat environment were found in four ecological assemblages. The influence degree of environmental factors on the fish community was especially discussed. The analyses results showed that environmental factors influencing fish assemblage structure include bottom temperature, water depth, bottom and surface pHs, surface total phosphorous and bottom dissolved oxygen.