| The water samples were collected from 13 typical sampling stations in Xiquanyan Reservoir and its upstream in May, July, August, September and October 2010, and collect zooplankton to qualitative and quantitative analysis. The research took the multivariate statistical to analysis the diversity and zooplankton community structure, used canonical correspondence analysis(CCA) to discuss the correlation ship between zooplankton and environmental factors, provided a reference for protection and management of the Xiquanyan Reservoir water resource.In this research, total of 86 species were identified, among which,22 genera and 29 species of protozoa, accounting for 33.72%; 21 genera,42 species of rotifer, accounting for 48.83; 6 genera,6 species of Cladocera, accounting for 6.98%; 6 genera,9 species of copepods, accounting for 10.47%. Average abundance and biomass were 55.0641 ind./L and 2.6887 mg/ L. Common species and dominant species of zooplankton are Rotifer, most of dominant species are rotifer in medium tolerance with pollution, the result of dominant species showed the water of Xiquanyan Reservoir had been in the state of moderate pollution.During the investigation, Shannon-Wiener diversity index are between 0.7758 and 3.0623. Annual results of the whole year showed that in Summer (Aug.)> Autumn(Sep.)> Autumn (Oct.)> Summer(Jul.)>Spring (May); Pielou evenness index J are Between 0.4723 and 0.8614 in the year, the annual performance is that Summer (Aug.)> Autumn (Oct.)> Summer(Jul.)> Autumn(Sep.)> Spring (May); Margalef index M are between 0.5735 and 2.3177, throughout the year, the annual performance of the Summer (Aug.)> Autumn(Sep.)> Summer(Jul.)> Autumn (Oct.)> Spring (May). H', J and M were the highest in Summer (Aug.), the lowest in Spring (May) throughout the year. Diversity index among all the samples,5#middle was the highest,2.858,12# was the lowest,1.778; uniformity index 10# was the highest,0.945,9#down is the lowest,0.572; Margalef index,7#down was the highest,2.048,12# was the lowest,1.200.May in Spring, the diversity index, Pielou index and Margalef index were the lowest, heavy pollution; July, August in summer, September in autumn and October, the diversity index, Margalef index and the Pielou index showed water state was in moderate pollution. According to the annual zooplankton diversity, the water in Xiquanyan Reservoir was already in the state of moderate pollution.Cluster analysis showed that zooplankton community structure was significantly different among all the stations in Xiquanyan Reservoir, May in Spring, August in Summer, September and October in Autumn of each station zooplankton community could be separated into three groups, July in Summer was separated into four groups. The groups of these stations results showed that the stations within the group zooplankton community were similar, of high variations in community composition between the groups. Zooplankton community structure in different seasons of the results of cluster analysis was not the same.Overall, in 10 environmental factors, in descending order, more significant environmental factors to the zooplankton species and spatial and temporal distribution in the reservoir area were CL, chla, COND, Depth, DO, and TN, more significant environmental factors to the zooplankton species and spatial and temporal distribution in the river area were Depth, chla, TP, PH, WT, TUR, TN, and CL. In the reservoirs and rivers environment, there were both the same and different point in the environmental factors impacted the zooplankton and its spatial and temporal distribution, moreover, the impact degrees were different.
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