Abstract: The community structure of copepods, including species composition, standing crops dynamics and diversities, was studied in a oligo-mesotrophic, large, deep-water lake — Qiandao Lake, Zhejiang. During one year of study, 16 species of copepods (5 Calanoida, 1 Harpacticoida and 10 Cyclopoida) were found. In terms of mean annual density of various species of copepods (copepodids+adults), the dominant species of Calanoida are Neodiaptomus schmackeri and Schmackeria forbesi, and the dominant species of Cyclopoida are Mesocyclops notius and Cyclops vicinus. The average density of copepods in the community is 46.81 ind./L, with biomass of 0.126 mg/L, and Margelef's diversity index of 1.54. The seasonal changes of standing crop of copepods is ranked summer>autumn>winter>spring, with the highest peak of copepod density (98.50 ind./L) and biomass (0.333 mg/L) in July to August, and the lowest copepod density (10.70 ind./L) and biomass (0.017 mg/L) in May. Station Ⅱ has the highest copepod density (80.10 ind./L) and biomass (0.289mg/L), station Ⅴ has the lowest copepods density (29.80 ind./L ), and station Ⅳ has the lowest copepods biomass (0.066 mg/L). Copepods diversity presents a maximum value of 3.21 in station Ⅰ,and a minimum value of 0.85 in station Ⅸ. The higher the transparency of the lake water, the lower the community diversities of Copepoda.