This paper investigated the macrobenthic biodiversity in Upper Reaches of Huangpu River from April 2005 to March 2006.The Shannon-Wiener index(H′), species eveness index(J) and richness index(D) were used to study the community structure, species assemblage, diversity of macrobenthos in Upper Reaches of Huangpu River. A total of 13 species were collected. Of these , the dominant species with high density were Limnodrilus hoffmeisteri , Bellamya aeruginosa and Corbicula fluminea, while the dominant species with high biomass were Corbicula fluminea and Bellamya aeruginosa. The Shannon-Wiener index(H′), species eveness index(J) and richness index(D) of Dianfeng were higher than those of Songpu Bridge. In seasonal variations, all of the three indices peaked in autumn, and were the lowest in summer, winter and spring respectively. According to the analysis of data, we found that the number of species and density have great effects on biodiversity; some environmental factors such as water temperature, water quality, habitat and human disturbance also affect biodiversity greatly.