During the investigation from August 2007 to April 2008, a total of 17 species of macrozoobenthos were recorded at 6sampling stations in Sandaohe Reservoir, Hubei Province, including 11 Chironomidae and 6 Tubificidae Oligochaetes. Procladius sp.was the dominant specie in spring while Microchironomus sp., Rheotanytarsus sp. and Procladius sp. were the dominant in summer.In autumn and winter Limnodrilus hoffmeisteri was the dominant. The species number, the density and biomass changed obviouslywith seasons. The seasonal density and biomass variation order were spring>winter>autumn>summer; and species number ranked assummer>winter>autumn>spring. The density and biomass of macrozoobenthos were 366.42±102.93ind./m²and 0.5649±0.1779g/m²respectively, which could be classified the reservoir as oligotropic level. The density and biomass increased from the front of dam tothe bay, and the Shannon-Wiener index, Margalef index and Pielou index were all at the highest in summer and the lowest in autumn.The density of Oligochaetes did not exceed 1000ind./m²in our surveys, which showed the water may be slightly polluted.