Abstract: Dazong Lake located in the middle of low-lying Lixiahe Region, a convergence area of the Yangtze River and the Huaihe River, and is one of the most important province-level protection lakes in Jiangsu Province. However, Dazong Lake is suffering serious environmental problems due to human activities in last two decades. Macrozoobenthos, an important part of aquatic ecosystems, contribute significantly to the circulations of energy and materials. In this study, macrozoobenthos community structure was investigated in Dazong Lake from 2015 to 2016 and 10 taxa macrozoobenthos were found. The average density of Oligochaeta, Chironomidae, Mollusca and other groups were 132.27, 100.52, 82.02, 5.29 ind./m2, while the average biomass were 1.52, 0.61, 168.74, 0.02 g/m2 respectively. The density and biomass of macrozoobenthos varied spatiotemporally. Branchiura sowerbyi, Limnodrilus hoffmeisteri, Tanypus chinensis, and Bellamya sp. were the dominant species in Dazong Lake. The results of water quality bioassessment using four different indexes (i.e. BPI, Shannon-wiener, Goodnight and Wright indexes) indicated that Dazong Lake was at the status of mild-intermediate polluted.