During the summer of 2010, the zooplankton community structure and physicochemical factors of Xiquanyan Reservoir, China, were surveyed. Seven evaluation methods were used to assess water quality, including the standing crop index evaluation method, the biological indicator method, diversity analysis, Q_B/T index, eu-mesotrophic/oligo-mesotrophic (E/O) index, fertility index method (E'), and physical and chemical factors evaluation method. Simultaneously, a canonical correspondence analysis (CCA) was used to analyze the correlations between the zooplankton community structure and environmental factors.The results showed that 33 genera comprising 56 species of zooplankton were found, including protozoa (14 species), rotifers (29 species), cladocerans (4 species), and copepods (9 species). The variety and quantity of zooplankton were the greatest at S5, and those at S1 were the lowest. The ordination of variety and quantity of zooplankton at each sampling site was S5 > S4 > S9 > S8 > S6 > S2 > S7 > S3 > S1. Rotifers were dominant in variety and quantity, with larger numbers and more species in the middle of the reservoir compared with the estuary area. Fifty-three species were typical indicators of environmental pollution, including ignoreprobity (10 species), o-β mesosaprobity (5 species), β-mesosaprobity (15 species), β-α-mesosaprobity (7 species), and α-mesosaprobity (16 species). Common species were Polyarthra trigla, Macrocyclops albidus, Microcyclops javanus, and Mi. inchoatus. Dominant species were Difflugia avellana, Filinia longiseta, Polyarthra trigla, Mi. inchoatus, and nauplius. The average species richness was 46.13 ind./L. Site S4 had the highest species richness (84.5%), and S1 had the lowest (0.5%). Of the four types of zooplankton, rotifers had the highest, and cladocerans had the lowest abundance. The species richness of protozoa was 9.53 ind./L, with S4 having the highest and S1 the lowest. The species richness of rotifers was 32.48 ind./L, S4 had the highest and S8 the lowest. The species richness of cladocerans was 1.33 ind./L, S5 had the highest and S2 the lowest. The species richness of copepods was 2.79 ind./L, S5 had the highest and S1 was the lowest. The average biomass was 0.137 mg/L, S5 had the biomass (39.8%), and S1 had the lowest (0.6%). Copepods contributed the most to biomass, whereas protozoa had the least contribution. The average Shannon-Wiener index of Xiquanyan Reservoir was 2.78, and the pollution level was β-mesosaprobity; Margalef richness index was 1.97, and the pollution level was α-mesosaprobity. Xiquanyan Reservoir had 5 oligo-mesotrophic (O) and 16 eu-mesotrophic (E) zooplankton species. The calculations of the Q_B/T index, E/O index, and E' index were 2.0, 3.2, and 2.28, respectively. The water quality evaluation determined meso-eutrophic and eutrophic levels based on bio-physical and chemical indices. The meso-eutrophic level was determined by chlorophyll a, total phosphorus content (TP), and transparency indicators; and the eutrophication level was determined by total nitrogen (TN) and dissolved oxygen indicators. According to the CCA, the horizontal axis had an extremely significant positive correlation with NO₃^-(P=0.95), NO₃^--N(P=0.75), and Cl^-(P=0.75), and the vertical axis had a significant positive correlation with NH₄⁺(P=0.71), TP(P=0.68), Chl a(P=0.60), and had a significant negative correlation with depth (P=-0.72)and COND(P=-0.72). NO₃^-, NO₃^--N, Cl^-, COND, depth, NH₄⁺, TP, and Chl a were the main factors affecting the quantity and distribution of zooplankton populations, and TN had little correlation with zooplankton. From the results, the water quality of Xiquanyan Reservoir was moderately polluted, and the eutrophication level was average. As an alternative source of drinking water for Harbin city, the water quality still requires improvement, and the water management and regulation should be enhanced.