Abstract: According to the data of eco-environmental survey from the shellfish-culture areas of Zhao'an Bay in March, June and September 2009, deleterious substances (such as Cu, Pb, Cd, Hg, As, petroleum, HCH, sulphide, DDT, PCBs, coliforms, Escherichia coli, DSP and PSP) in seawater, surface sediments and fishery organisms were detected and analyzed. Eco-environmental qualities of those areas were assessed and classified by single index method of seawater quality, surface sediment quality or shellfish-culture quality, and synthesis assessment index method of the whole eco-environmental quality. The results showed that the quality grades of seawater, surface sediment and shellfish-culture, all ranged from grade 2 to grade 6, with an average of grade 3, grade 4 and grade 2, respectively. The shellfish-culture areas' eco-environmental quality grade also ranged from grade 2 to grade 6, mean of grade 3. Overall, the quality of eco-environmental survey in the shellfish culture areas of Zhao'an Bay was in relatively good level, since the quality was relatively good level by seawater, general level by surface sediments and good level by shellfish-culture areas. And the major contaminants were petroleum, Escherichia coli, DDT and PCBs. There was no area in the shellfish areas of Zhao'an Bay belonged to the first kind or natural background. And there were 15 areas belonged to the second kind, occupying 88% of all areas, while 2a kind in clean had 6 areas, occupying 35% of all areas, 2b kind in relatively clean had 5 areas, occupying 30%, 2c kind in light pollution had 4 areas, occupying 24%. In addition, there were 2 areas belonged to the third kind, while 3a kind in middle pollution or 3b kind in serious pollution had one area occupying 6%, respectively. It was the same with the results of eco-environmental synthesis assessment and categorization of Zhao'an shellfish regions and its environmental pollution present situation.