This experiment was conducted to study the effects of dietary vitamin E level on immune and antioxidant functions of geese, and find out the optimal dietary vitamin E supplemental level for geese aged 1 to 12 weeks. One hundred and eighty 1-day-old Qingnonghui geese with an average body weight of (111.1?6.5) g were randomly selected and divided into 6 groups with 3 replicates per group and 10 geese per replicate. The geese in the 6 groups were fed the basal diets supplemented with 0 (control group), 5, 10, 20, 40 and 80 IU/kg vitamin E, respectively. The experiment lasted for 12 weeks. The results showed as follows: 1) compared with the control group, the thymus index of geese aged 4 and 12 weeks in 10, 20, 40 and 80 IU/kg vitamin E groups was significantly increased (P<0.05 or P<0.01), and the index of Bursa of Fabricius of geese aged 4 and 12 weeks in 20, 40 and 80 IU/kg vitamin E groups was significantly increased (P<0.05 or P<0.01). The antibody titre of Newcastle disease at 7, 14 and 21 days after immunization was significantly increased by the supplementation of 20 IU/kg vitamin E (P<0.05 or P<0.01). At the age of 4 and 12 weeks, the supplementation of 20, 40 and 80 IU/kg vitamin E could significantly enhance the lymphocyte transformation rate in peripheral blood of geese (P<0.05 or P<0.01). 2) The glutathione peroxidase (GSH-Px) activity in serum and liver of geese aged 4 weeks in 20, 40 and 80 IU/kg vitamin E groups and aged 12 weeks in 10, 20, 40 and 80 IU/kg vitamin E groups was significantly improved compared with the control group (P<0.05). Compared with the control group, the serum total superoxide dismutase (T-SOD) activity of geese aged 4 weeks in 40 IU/kg vitamin E group was significantly improved (P<0.05), the liver T-SOD activity of geese aged 4 weeks in 10 IU/kg vitamin E group was significantly improved (P<0.05), and the liver T-SOD activity of geese aged 12 weeks in 20, 40 and 80 IU/kg vitamin E groups was significantly improved (P<0.05). At the age of 4 weeks, the serum total antioxidant capability (T-AOC) in 40 IU/kg vitamin E group and the liver T-AOC in 20 IU/kg vitamin E group were significantly higher than those in control group (P<0.05); at the age of 12 weeks, the serum T-AOC in 20, 40 and 80 IU/kg vitamin E groups was significantly higher than that in control group (P<0.05). 3) The serum and liver malondialdehyde (MDA) content of geese aged 4 and 12 weeks in vitamin E supplemental groups was decreased in different degree and the serum catalase (CAT) activity of geese aged 4 and 12 weeks in 40 IU/kg vitamin E groups was significantly improved compared with the control group (P<0.05). In conclusion, 1) vitamin E supplementation can improve the immune and antioxidant functions of geese. 2) The optimal dietary vitamin E supplemental level for geese aged 1 to 12 weeks is 44.31 to 53.11 IU/kg in the best immune and antioxidant conditions according to the calculation by the established regression equation. According to the serum MDA content, the minimum dietary vitamin E supplemental level for geese aged 1 to 12 weeks is 6.84 IU/kg.