From 2007 to 2008, a monthly investigation was conducted to study the zooplankton community structure and water environmental factors in Qiandao Lake. A total of 115 species of zooplankton were identified including 4 groups i.e. Protozoa (16 species), Rotifer (51 species), Cladocera (23 species) and Copepoda (25 species). Horizontal and temporal distributing characters of zooplankton communities were analyzed. Density of zooplankton presented a pattern of single peak in spring in two years ,peaked at 840.9 ind./L in May 2007, 850.5 ind./L in june 2008 separately; Biomass of zooplankton presented two-peak in spring and autumn , peaked at 1.89 mg/L in May 2007, 0.837 mg/L in August 2007, 1.63 mg/L in May 2008年、0.802 mg/L in August 2008. Densiey and biomass of zooplankton decreased sequentially as the following order:river region > transition zone > lake region . According to the variety in vertical distribution,density of zooplankton were distributed throughout every layer of water body, reaching the biomass maximum at the depth of 4 meter in river region(sampling 1 ) and transition zone (sampling 4) , and reaching the biomass maximum at the depth of 8 meter in lake region (sampling 9) .The significant factors affecting zooplankton distribution were DO, CODMn, water temperature, TN, NO2-N, TP, NO3-N. Biomass of Protozoa and Copepod were positively correlated with DO, the biomass of Rotifer and Cladocera were positively correlated with TN, NO3 and the biomass of phytoplankton.Canonical correspondence analysis ( CCA) was applied to explore the relationship between variation of dominant species of zooplankton and environmental factors. The results showed that certain species, such as Tintinnidium entzii,T.fluviatile,Daphnia hyalina were positively associated with DO as well as negatively associated with water temperature. Among other species, Keratella.tcinensis,Bosmina coregoni,B.longirostris were correlated positively with TP,TN,NH3-N ,NO3- while Hexarthra.mira, Mesocyclops leuckarti were showed positive correlation with Chla. Most Copepoda such as Mesocyclops leuckarti, Neutrodiaptomus incongruens were positively associated with water temperature. Meanwhile, the biomass of Daphnia was positively correlated with biomass of phytoplankton from February to june, negatively correlated with water temperature in other month.