To understand the spatial and temporal distribution pattern of the fish communities in the south of northern Jiangsu shoal, seasonal bottom trawl surveys were conducted in May (spring) and September (autumn) of 2010 in the area. The dominant fish species, the impacts of the environment on the distribution of the fish communities, spawning and feeding habitat of dominant fish were also discussed. The result indicated that numerically the average density was 1.33×10³ ind/km² in spring and 2.02×10³ ind/km² in autumn, respectively. The average weight density was 76.35 kg/km² in spring and 35.12 kg/km² in autumn, respectively. The spatial distribution pattern was the same in spring and autumn, i.e. the density was higher in the near shore than that in the neritic waters. Generally, the species number was higher in autumn than that in spring. The distribution patterns of fish species and fish diversities are also similar to the density, and the value was higher in the near shore than in the neritic. Stepwise regression showed that the weight density or individual density was significantly related to the water depth, the fishes were abundant in near shore than in the neritic waters. In spring, numerically Larimichthy spolyactis was predominant species, whereas Miichthy smiiuy was most important dominant species by weight. In autumn, Collichthys lucidus was the predominant species both in number and in weight. Compared to the other coastal waters, the south of northern Jiangsu shoal was mainly composed of economically important fishes. Our study indicated that the northern Jiangsu shoal and its outer waters were important spawning and nursery ground for many economically important fishes. The northern Jiangsu shoal plays a role in completing the life histories for many economically important fishes of the Lvsi fishing ground.