This experiment was conducted to investigate the effects of dietary sodium humate on growth performance, immune function and antioxidant capacity of broilers. Six hundred 1-day-old healthy Arbor Acres (AA) broilers were randomly allocated into 5 groups with 12 replicates (males and females in half) per group and 10 broilers per replicate. Five groups were antibiotic control group (T1), non-antibiotic control group (T2), 0.1% (T3), 0.3% (T4) and 0.5% sodium humate supplemental groups (T5), respectively. The experiment included 2 stages of early stage from 1 to 21 days of age and later stage from 22 to 42 days of age. The results showed as follows:1) average daily gain of male broilers in antibiotic control group and 0.3% sodium humate supplemental group was significantly higher than that in 0.1% and 0.5% sodium humate supplemental groups from 1 to 21 days of age (P<0.05). 2) Dietary sodium humate had no significant effects on dressing percentage, semi-eviscerated percentage, eviscerated percentage, breast muscle percentage, leg muscle percentage and abdominal fat percentage of broilers at 42 days of age (P>0.05). 3) Spleen index of male broilers and thymus index of female broilers in antibiotic control group were significantly higher than those in non-antibiotic control group and 0.1% sodium humate supplemental group at 42 days of age (P<0.05). 4) At 21 days of age, the contents of immunoglobulin A (IgA) and immunoglobulin G (IgG) in serum of broilers in 0.3% and 0.5% sodium humate supplemental groups were significantly higher than those in antibiotic control group and non-antibiotic control group (P<0.05), and the content of immunoglobulin M (IgM) in serum in 0.5% sodium humate supplemental group was significantly higher than that in the other groups (P<0.05). At 42 days of age, the contents of IgA and IgM in serum of broilers in 0.5% sodium humate supplemental group were significantly higher than those in the other groups (P<0.05). 5) At 21 days of age, the content of malonaldehyde (MDA) in serum of broilers in 0.3% and 0.5% sodium humate supplemental groups was significantly lower than that in antibiotic control group, non-antibiotic control group and 0.1% sodium humate supplemental group (P<0.05), and total antioxidant capacity (T-AOC) in serum was significantly higher than that in antibiotic control group, non-antibiotic control group and 0.1% sodium humate supplemental group (P<0.05). At 42 days of age, the content of MDA in serum of broilers in antibiotic control group was significantly higher than that in the other groups (P<0.05), and T-AOC in serum in 0.3% and 0.5% sodium humate supplemental groups was significantly higher than that in antibiotic control group (P<0.05). Combined growth performance, immune function and antioxidant capacity, it is suggested that the appropriate dosage of sodium humate in the diet of broilers is 0.3% to 0.5%.