Lake Fuxian is a representative deep plateau lake located in Yunnan Province, China. To describe crustacean zooplankton's responses to ecological changes, we carried out studies on its community structure and spatial distribution. Altogether 8 taxa of crustacean zooplankton were founded in Lake Fuxian from June to July in 2005, and the average community density 27.6ind./L dominated by Copepoda. Dominant species of Copepoda were Phyllodiaptomus tunguidus Shen et Tai, and dominant species of cladoceran were Ceriodaphnia cornuta Sars and Bosmina sp. Crustacean zooplankton was mainly distributed from surface to 30m vertically, and its density decreased with the depth increase. Cladocera and Nauplii had the dominance in 0-10m layer, but Copepoda had the dominance when depth down to 10m. Average density of crustacean zooplankton was significantly higher in south lake than north lake (P<0.01), while there were no significant differences in average density between near shore region and open water region,and between macrophyte distributed region and no macrophyte distributed region (P>0.05). Correlation analysis indicated that there was significant correlation between the vertical density of crustacean zooplankton and algae density or water physical-chemical factors, but there was no significant correlation between the horizontal density and algae density or water physical-chemical factors. Compared with the surveys in 1980s, Neutrodiaptomus mariadviagae mariadviagae (Brohm), one of the dominant species of crustacean zooplankton, disappeared in the lake and was replaced by P. Tunguidus, which was probably caused by introduction of Neosalanx taihuensi Chen. The density of crustacean zooplankton showed an increasing tendency, but that was still rather low, likely a result of increased nutrient levels and predation by N. Taihuensi