Using factor analysis on quantitative data collected monthly from 1982 to 1985 and seasonal 1992 to 1995 surreys in the Bohai Sea revealed the spatiotemporal patterns of the fish community there. As increasing in species for specific month, number of principal representative components (PRCs )were significantly positively related under cumulated variation for eigenvalues more than 80%(r=0. 9051, df=10, p<0. 001). Seasonal dynamics of species alternation showed that the community was dominated by both warm-temperate and warm water faunistic PRCs which occurred only once the annually.Spatially, stations 19, 20 and 25 in the Bohai Strait ware the most abundant during the cold months (December through April) and from September and October. In other months, the biomass of PRCs was # negatively dependent to the isobath in Liaodong Bay and Laizhou Bay. Station assemblages were overlapped throughout half as the whole Bohai Sea in colder season and more than 1/3 of the Bohai Sea in warmer one. The resulting spatial structures of biomass were due to the fact that many former dominants disappeared because of natural degradation of the ecosystem and anthropogenic impacts on the biological community. The more equal distribution of fewer PRCs, at present, resulted in fewer dominants in the community succession, wider ecological niche, and nearly unique spatial structuring of low biomass.