From Nov. 2004 to Aug. 2005, based on macrobenthic samples collected seasonally from 12 intertidal stations in Qitou, Damen Island, Nanyue, Ximen Dock around the Yueqing Bay, the macrobenthic community and spatio-temporal variation of intertidal zone of the Yueqing Bay were analysized. We found a total of 65 species, belonging to 37 families, 9 classes and 7 phyla, most of them were arthropods and the mollusks. The density and biomass of four seasons including spring, summer, autumn and winter were 469.33±70.28 ind./m^2, 126.02±26.96 g/ m^2; 628±67.6 ind./m^2, 261.79±58.06 g/m^2; 494.67±72.62 ind./m^2, 103.90±23.25 g/m^2; 358.67±43.75 ind./m^2, 59.49±12.66 g/m^2. Densities were not significantly affected by tidal flats nor seasons (F=1.897 and F=1.057, P>0.05) but biomass differences were marked among seasons (F=3.695, P<0.05). The value of Margalef’s species richness index and Shannon-Wiener’s index was as follows: summer>spring>winter>autumn, the value of Pielou’s index was: spring>winter>summer>autumn, the value of Simpson’s index was: autumn>winter>summer>spring. The spatio-temporal variation of benthic community structure in Yueqing Bay was studied by hierarchical clustering and no-metric multidimension scaling. The results showed that location, the tidal flat and season were the three most important factors which greatly impact on spatio-temporal variation of benthic community structure in Yueqing Bay.
