This experiment was aimed to investigate the effects of dietary different levels of vitamin A (VA) on growth performance, immunity and antioxidant function of broilers. A total of 240 one-day-old healthy AA broilers (half male and half female) were randomly allotted into five groups with six replicates of eight broilers each. The trial lasted for 42 days. Broilers were fed corn-soybean basal diets with five levels of VA (3 000, 6 000, 15 000, 30 000 and 45 000 IU/kg) in a single factorial arrangement. The results showed as follows:1) dietary different levels of VA had significant effects on average daily gain (ADG), average daily feed intake (ADFI) of broilers from 22 to 42 days of age, and ADFI of broilers from 1 to 42 days of age (P<0.05), feed/gain (F/G) of broilers from 22 to 42 days of age showed a significant decreasing trend (0.05 ≤ P<0.10), and ADFI of broilers from 22 to 42 days of age and 1 to 42 days of age and F/G of broilers from 1 to 42 days of age showed a linear increase with the increase of VA supplemental levels (P<0.05 or 0.05 ≤ P<0.10), among which, the weight gain of broilers in the 3 000 IU/kg group was poor, and the weight gain in the 6 000 IU/kg and 15 000 IU/kg groups was higher and the F/G was lower. In the 30 000 and 45 000 IU/kg groups, the ADFI was higher, and the F/G was increased to varying degrees. 2) Dietary supplementation with different levels of VA had significant effects on serum interleukin-1 (IL-1) content at 21 days of age and serum IL-1, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) contents at 42 days of age (P<0.05), and had a significant effect trend on serum interleukin-2 (IL-2) content at 42 days of age (0.05 ≤ P<0.10). Among them, 3 000, 6 000 and 45 000 IU/kg groups had lower the content of serum immune factors and 15 000 IU/kg group had higher levels. 3) Dietary supplementation of different levels of VA had significant effects on serum glutathione peroxidation (GSH-Px) activity at 21 days of age and GSH-Px and catalase (CAT) activities at 42 days of age (P<0.05), and the serum malondialdehyde (MDA) content at 21 days of age with the increase of VA level showed a significant increasing trend (0.05 ≤ P<0.10), the serum MDA content and total superoxide dismutase (T-SOD) activity at 42 days of age with the increase of VA level were significantly linear or quadratic increased (P<0.05), and 45 000 IU/kg group had higher serum MDA content and lower T-SOD activity. In summary, the addition of VA at 6 000 and 15 000 IU/kg under this test condition will allow broilers to obtain better growth performance,and 15 000 IU/kg can also meet immunity and antioxidant status in broilers. When needed, the growth performance and immunological antioxidant function of broiler chickens both decrease when added 30 000 and 45 000 IU/kg VA.