Abstract: The changes in total polyphenols contents and antioxidant activity of rosemary extract during simulated gastrointestinal digestion process were investigated in this work,and the relationship between the contents of total polyphenols and the antioxidant activity was verified. The results showed that the total polyphenols contents in the digestive products of rosemary extracts increased significantly during the in vitro gastric digestion,while the simulated intestinal digestion resulted in the substantial loss of phenolic compounds(P<0.05). After the simulated gastric digestion for 180 min,the total polyphenols contents in the digestive products increased by 17.88%(P<0.05). However,the total polyphenols contents decreased by 19.64% after the simulated intestinal digestion for 120 min(P<0.05). Following the simulated gastric digestion for 180 min,the scavenging activities of the digestive products against DPPH radical and superoxide radical increased by 20.36% and 22.07%(P<0.05),respectively. Moreover,the ferric ion reducing antioxidant power(FRAP)increased by 11.76%(P<0.05). However,following the simulated intestinal digestion for 120 min,the scavenging activities of the digestive products against DPPH radical and superoxide radical were reduced by 74.08% and 50.00%(P<0.05),respectively,and the FRAP value decreased by 52.13%(P<0.05). In addition,there was a positive relationship between the antioxidant activity potential and the total phenolic of the digestive products. In summary,the simulated gastrointestinal digestion results in significant influences on the total polyphenols contents and antioxidant activity of rosemary extract.