Abstract: During the period from March to December 2010, four sampling surveys were carried out to study population, density and biodiversity of macro zoobenthos in the mangrove forest around the Dongzhai Harbor, and their temporal and spatial variations. It was found that the differences were very significant between seasons in population and diversity. The animals were the most diversified in winter (45 species found) and the least in summer (28 species found). The highest biomass was observed in autumn (272.78 g•m^-2) and the lowest in summer (165.93 g•m^-2). The highest density was observed in winter (679.25 m^-2) and the lowest in summer (504.95 m^-2). Two-factor ANOVA was used to analyze effects of station and season on density, biomass and evenness index of the macro zoobenthos (Shannon-Wiener, H; Margalef, D_M; Simpson, E). It was found that the temporal variations of the density, biodiversity and richness indices were significant (P＜0.05) and the spatial variations of the biomass and evenness indices were significant (P＜0.05). The analysis also indicates that temperature, salinity and , substrate and species of mangrove are the leading factors affecting biodiversity of the macro zoobenthos. Restoration of the mangrove forest around the Dongzhai Harbor will help increase biomass and species diversity of the macro zoobenthos therein.

Key words: mangrove, macro benthic, species diversity, Dongzhai Harbor