This experiment was conducted to study the effects of musca domestic larval peptide on antioxidant abilities and immune indices in rat. Ninety-six SD rats were randomly allocated to 4 groups with 4 replicates each and 6 rats in each replicate. Rats in control group were fed basal diet and in trial group were fed experimental diets which were supplemented with 0.2%, 0.5% and 1.0% musca domestic larval peptide, respectively. The trial lasted for 21 d with 7 d of adjustment period. The results showed that there were no significant differences on antioxidant and immune indices among all groups before experiment （P>0.05）. There were no significant differences on antioxidant and immune indices in control group during the experiment time. From 7th d, compared with control group, the serum MDA concentrations in all trial groups were decreased significantly（P<0.05）, and the activities of CAT, GSH-Px, SOD and the immune indices such as spleen coefficient, thymus coefficient, concentrations of serum IgA, IgG and lysozyme content were significantly increased in trial groups Ⅱ and Ⅲ（P<0.05）. It was concluded that musca domestic larval peptide had high biologically activity, and the optimal supplemental dosage of musca domestic larval peptide was 0.5%.