The experiment was conducted to study the effects of dietary copper levels on the immunity and the activity of anti-oxidation enzyme in serum of growing-laying hens. Two hundred and sixteen 9-week-age Hailan brown growing laying hens were randomly divided into 6 groups with 3 replicates each and 12 hens in each replicate. Chickens in group Ⅰ were fed basal diet, and group Ⅱ~Ⅵ were fed diets supplemented with 6.5, 30.0, 60.0, 125.0 and 250.0 mg/kg copper (CuSO4·5H2O), respectively. The trial lasted for 49 days, including preset period for 7 days and test period for 42 days. The results showed that: 1) the index of immune-organ in group Ⅲ was significantly increased compared with that in other groups (P＜0.01), and the indices of bursa of Fabricius and spleen in groups Ⅰ and Ⅵ were significantly reduced compared with those in other groups (P＜0.01), and the indices of thymus in groups Ⅰ and Ⅵ were significantly reduced compared with those in other groups in 16 weeks age; 2) activities of serum anti-oxidation enzyme (ceruloplasmin, Cu/Zn-SOD, catalase, GSH-ST) in group Ⅲ were significantly increased compared with those in other groups (P＜0.01), and the activities in group Ⅵ were significantly reduced compared with those in other groups (P＜0.01); and serum MDA content in group Ⅲ was significantly reduced compared with that in other groups (P＜0.01), and MDA contents in groups Ⅰ and Ⅵ were significantly increased compared with those in other groups; 3) lymphocyte transformation rate in group Ⅲ was significantly increased compared with those in other groups (P＜0.01), the rates in groups Ⅰ, Ⅴ and Ⅵ were significantly reduced compared with those in other groups (P＜0.01), and antibody valence of Newcastle disease in serum in group Ⅲ was significantly increased compared with that in groupsⅠ, Ⅱ, Ⅴ and Ⅵ (P＜0.05 or P＜0.01). In conclusion, the appropriate supplementation of copper in diet of growing laying hens is 30.0 mg/kg (the actual content of copper in basal diet is 4.85 mg/kg).［Chinese Journal of Animal Nutrition，2011，23（1）：154-161］