A comparative study on the horizontal distribution of crustacean planktons was carried out in three different areas(water lily vegetation area, littoral zone and pelagic zone) in Lake Xuanwu on July 31, 2010. The relationship between distributions of crustacean planktons and environmental factors was analyzed. The results showed that the abundance of crustacean planktons was significantly higher in the water lily vegetation area than in the littoral and pelagic zone. The dominant species of cladocera during the survey were Diaphanosoma dubium, Moina micrura, Alona sp. and Scapholeberis kingi. Mesocyclops pehpeiensis and Thermocyclops taihokuensis dominated the copepod community. Comparing to other areas, most species of crustacean planktons were occurred in the water lily vegetation area, such as a rare cladocera Neodiaphanosoma volzi. Redundancy analysis showed that the most important factors impacting on the horizontal distribution of crustacean planktons were concentrations of total suspended solids, chlorophyll-a and total dissolved phosphorus. Thus, aquatic macrophytes such as water lily vegetation might provide adequate refuge to crustacean planktons with poor swimming ability, and might be one important factor to determine the horizontal distribution of crustacean planktons in Lake Xuanwu.