Seasonal investigations on zooplankton community in Liusha Bay were carried out from May 2012 to January 2013. A total of 41 species and 17 groups of pelagic larvae were recorded, in which the copepod was the majority (29 species). Subeucalanus subcrassus, Brachyuran larva and Macruran larva were the dominant species seasonally in three quarters. The annual average density and biomass were 48.12 ind./m3 and 13.43 mg/m3, respectively. In general, the density, biomass and diversity index of zooplankton were lower in autumn than those in spring and summer, and these indices in inner bay were lower than those in outer bay. The zooplankton density was barely positively correlated to nitrite, while the zooplankton biomass had significant correlations with multiple environmental factors such as nitrite, ammonium and total nitrogen. Compared with the control (non-culture area), the density and biomass in the main scallop culture area, the fish culture area and the oyster culture area were lower. Rarely found in culture areas, large and medium-sized zooplankton mainly appeared in the non-culture area. In autumn, the density of Acartia erythraea was higher in the fish culture area than those in the other areas. During winter, the diversity index of zooplankton in the main scallop culture area was the highest (2.97). Large and medium sized species of zooplankton mainly appeared in the control area in all reasons. In spring, Subeucalanus subcrassus appeared with absolute predominance (66.04%) in the control area. In summer, the biomass of S. subcrassus and Flaccisagitta enflata were the highest in the control area (accounting for 0.3% and 0.8%, respectively) and the lowest in the main scallop culture area (accounting for 0 and 0.8%, respectively). In autumn, a spot of A. erythraea were merely found in the control area and the fish culture area. The density and biomass in the main scallop culture area were rapidly increased from autumn to winter, although they were lower than those in the non-culture area but higher than those in the fish culture area and the oyster culture area. The results indicate an obvious decline in the density and biomass of zooplankton and a severe miniaturization of zooplankton in size in Liusha Bay with the culture of fish and shellfish.