In this paper, the assessment results of phytoplankton, chlorophyll, primary production, zoobenthos of the without aquarulture range in tidal zone and the shallow sea, fouling zoo of filtration and without aquaculture Of the hanging culture range were investigated in Tong' an Bay during 1998. The carrying capacity of Tong' an Bay for the culture of shellfish are estimated by the nutrition dynamic model and the coast enery flowing analysis method. The optimal optimal areas of shellfish culture and its major kinds are calculated through statistics analysis. The results are that the carrying capacity of culture of shellfish is 45546 t (with weight of shell) and that the optimal farming areas is 3027 hm2. Among which the oyster of adhesion stone for culture is 2280hm2, the oyster of hanging for culture is 500hm2, Sinoncuacula constricta is 95hm2, Rnditapes pholippinarum is 120hm2, Perna viridis is 25hm2. Since 1994, the actual farming area exceeded the optimal farming area, and the yield of unit has been decreased year after year. The diseases have been taken place constantly. The Bay culture and its distribution are arranged on the basis of above mentioned optimal farming area. The alage culture are proper arranged to preverted taking place red plankton bloom for the water having over full nutrition.