Abstract: Antioxidant activity and bioavailability of the Pacific cod(Gadus macrocephalus) protein peptide were determined during in vitro gastrointestinal digestion model and Caco-2 cell monolayer model simulated the process of gastrointestinal digestion and absorption. The results showed that TEAC activity of fish protein peptide had no obvious variation during gastrointestinal digestion,while DPPH scavenging capacity significantly(p <0.05) reduced after pepsin digestion and obviously picked up but below(p <0.05) the level of before digestion after intestinal digestion. The peptide nitrogen content and antioxidant activity of the absorption components increased(p<0.05) during absorption. The bioavailability of protein peptides was higher than fish meat(9. 1 %), especially, low- molecular- weight fraction of protein peptides had the highest bioavailability(46.2%). The cod protein peptide had antioxidant activity and pretty bioavailability after gastrointestinal digestion and absorption,which provided theoretical evidence for the cod protein peptide development.