) with initial body weight of (15.30?.03) g were fed experimental diets supplemented with six small peptide levels of 0% (control group), 0.25%, 0.50%, 0.75%, 1.0% and 1.5%. Three replicates were used for each group with 30 fish per replicate. The experiment lasted for 56 days. In addition to the amylase activities of the hepatopancreas, digestive enzyme activity in three tissues (stomach, intestine and hepatopancreas) of P. ), which showed a trend of an early increase and later decrease with the small peptide levels increasing. The small peptides significantly reduced the (MDA) content of the hepatopancreas and serum (<), and increased total antioxidant capacity (T-AOC) of serum in the 1.0% and 1.5% small peptide groups. There was no significant difference in superoxide dismutase (SOD) and glutathione reductase (GR) of the hepatopancreas (>). SOD and glutathione peroxidase (GSH-Px) of serum in the1.0% and 1.5% small peptide groups, and GR of serum in the 0.75% and 1.0% groups were all significantly higher than in the control group (<). The phenylalanine content in the experimental groups was significantly higher than in the control group (<>). ∑PUFA in the 0.75% and 1.0% groups, and DHA and EPA in the 0.50% and 1.0% groups were all significantly higher than the control group (>). Overall, appropriate small peptide supplementation can effectively enhance digestive enzyme activities and antioxidative capability of and improve the fish quality to some extent.