The experiment was conducted to investigate dietary zinc level on growth performance, antioxidant capacity, immune function and zinc deposition in yellow broilers aged from one to twenty-one days, and to estimate the optimal dietary zinc level for yellow broilers by NLIN. A total of 1 440 one-day-old male broilers were randomly assigned to six dietary treatments with six replicates of forty birds. The treatments received the same basal diet supplemented with 0, 20, 40, 60, 80 and 120 mg/kg zinc from zinc sulfate (ZnSO4·H2O), respectively. The feeding trial lasted for 21 days. The results showed that adding zinc significantly improved average daily gain of broilers (P<0.05), addition with 80, 120 mg/kg zinc significantly increased feed intake of broilers (P<0.05), and supplementation with 60 mg/kg zinc significantly decreased ratio of feed to gain of broilers (P<0.05); zinc supplementation significantly increased the content of GSH, Zn and MT, as well as the activities of GSH-Px, CuZnSOD and AKP in serum (P<0.05), and significantly raised zinc content in tibia and MT content in liver (P<0.05), and addition with 60 mg/kg zinc showed the best result for AKP activity in serum and zinc content in tibia; supplementation with 40 mg/kg zinc significantly elevated spleen index (P<0.05), and addition with 20 to 80 mg/kg zinc significantly improved thymus index and index of bursa of Fabricius of broilers (P<0.05). Based on the criteria including ADG, serum AKP activity and tibia zinc content, the estimated requirement of zinc was 85 mg/kg, but the optimal zinc levels estimated by NLIN were 99, 96, 93 mg/kg, respectively.［Chinese Journal of Animal Nutrition, 2010，22（2）:301-309］