Marine fishery catch can be divided into three groups, including finfish, crustaceans and cephalopods. They tend to share the habitats within the same ecosystem, and interact with each other via ecological processes such as predator prey and competition for spawning and feeding grounds. Ecosystem-based fisheries management, repeatedly called in the management of international and domestic fisheries resources, requires a good understanding of such dynamic interactions of all the organisms and their habitats. However, most studies about the three groups of marine organisms are still done separately, lacking a comprehensive understanding of the relationships among them. Based on data collected from a bottom trawl survey in 2000 in the East China Sea, we conducted a preliminary study to evaluate spatial relationships among the concentration areas of the three groups of organisms in four seasons and the distances among the three groups of organisms and their seasonal regulations. The study shows that there is a trend of spatial separations among concentration areas of the three groups of organisms, with an increased trend of isolations. The trend is thought to be the consequences of competitions among the three groups of organisms, of adaptations to each other, and of a long-term evolution, showing a typical niche differentiation. Distances between the three groups of organisms in four seasons were relatively far in spring and summer, but close in autumn and winter. This could result from the majority of fishes spawning in spring and summer, during which they tend to aggregate on the spawning grounds or egg rearing grounds, while the other organisms do not aggregate or aggregate in different areas, which caused an increased distance between fishes and the other organisms. Most organisms need to migrate for feeding and overwintering in autumn and winter, and they distributed separately to some extend, which leads to relatively close distances among the three groups of organisms. The distance between cephalopods and fish were close, and those between fish and crustaceans, crustaceans and cephalopods, were relatively far, probably resulting from for different swimming abilities of the three groups of organisms. Crustaceans swimming ability tend to be poor, generally remaining close to the ocean bottoms; cephalopods tend to have stronger swimming ability than crustaceans, being more active in water columns, but still with limit of intermittent swimming characteristics; and fishes have the strongest swimming ability, sustained long-term stays in water columns. The different swimming abilities of the three groups of organisms made fishes and cephalopods have access to more habitats available compared to crustaceans. Spatio-temporal distributional characteristics of the three groups of organisms can have significant implications to fisheries management.