Abstract: Based on the data collected from eight stations of Pearl River Estuary (August 2006), the species composition and spatial distribution of zooplankton in Pearl River Estuary were determined. Results showed that 57 species in total were identified. Among them copepod was the dominant group, containning 20 taxa. The zooplankton community was composed of 18 rotatoria species, 8 cladocera species, 2 tunicata species, and 1 species in each of Protozan, polychaeta, heteropoda, medusae and euphausiacea, and 2 species unidentified. There were also some larva of copepod and macrura in different developmental stages. Brachionus calyciflorus, B.falcatus and Bosmina longirostris appeared in each station. Species numbers ranged from 19 to 29 among stations. The range of density variation was from 2 288 to 300 000 indm-3. The range of biomass variation was from 10.03 to 111.94 mgm-3.