Abstract: The macrobenthic community structure was investigated in 16 monitoring stations in an enclosed tideland for cultivation in Qingduizi bay in spring, summer, autumn and winter of 2011-2012 in order to evaluate the effect of reclamation on the nearshore macrobenthoc community structure by ABC curve and Cluster Analysis(CLA). It was found that the offshore macrobenthoc community structure was disturbed obviously, with significant decrease in species number, and density and biomass in the habitat, especially the economically imporant species compared with previous data. There was significantly lower macrobenthoc species number, and habitat density, and biomass in nearshore than in far shore. ABC curve and CLA analysis revealed that the more degree of disturbance and lower similarity degree of macrobenthoc community were observed in the surveyed areas, indicating that the reclamation leads to form a number of different types of habitats offshore sedimentary environment.