The four south lakes of Shandong province is four connectedlakes (Weishan Hu, Dushan Hu, Zhaoyang Hu and Nanyang Ru) with anarea of 119 thousand hectare. The average depth of water is 1.5 meters and theaverage annual production of fish is about 94.05kg/ha. The investigation was made in 1983-1984. In the lakes the amount of dissolvedoxygen was 8.71 mg/L. and pH value was 7.1-9.7. The amount of PO_4-P was0.0108 mg/L. The amount of NO_8-N, NO_2-N and NH_4-N was 0.465 mg/L. Thebiomass of equatic plant was 2584.2 g/m. Annual biomass of phytonplanktonand zooplankton were 1.709 mg/L and 0.601 mg/L, respectively. The avera-ge annual biomass of zoobenthos was 92.65 g/m. Seven predominant speciesof fish in the lakes were: Carassius auratus (Linnaeus), Pseudobagrus fulvidrco(Richardson), Ophiocephalus argus (Cantor), Calter erythropterus (Basilewsky),Parabramit pekinensis (Basilewsky), Parasilurus asotus (Linnaeus) and Cyprinuscarpio (Linnaeus). The water in four lakes was rich in nitrogen but poor in pho-sphates, thus the utility of the total primary production by the fishes in thefour lakes was only 0.495%. We also analysed the ecosystem structure of the fishes in the four lakes. Atentative proposal was suggested in order to exploite and utilize the aquatic resour-ces in the four lakes.