In order to compare the effects of gastric and intestinal digestion on the digestive stability of Macrobrachium nipponense in adults and infants， static digestion models of adult and infants were constructed to digest tropomyosin (TM) in vitro. Then， Tricine-SDS-PAGE， RP-HPLC and MALDI-TOF-MS were used to determine the degree of hydrolysis of TM， the concentration of acid-soluble peptide and the molecular weight distribution of digestive products in stomach and intestine after the simulated digestion in vitro. The results showed that the hydrolysis degree of TM in the final stage of gastric digestion in simulated adults and infants was (17.99±1.41)% and (49.46±1.02)%， respectively. The degrees of TM hydrolysis in the final stage of intestinal digestion in simulated adults and infants were (9.92±1.50)% and (30.68±1.04)%， respectively. The mass concentrations of acid-soluble peptides at the final stage of gastric digestion in simulated adults and infants were (74.77±6.84) μg/mL and (46.39±7.5) μg/mL， respectively. The mass concentrations of acid-soluble peptides at the final stage of intestinal digestion in simulated adults and infants were (303.99±12) μg/mL and (175.93±11.53) μg/mL， respectively. In the final stage of simulated adult stomach and intestine digestion， the digestive fragments of TM were mainly distributed in the range of 15-30 ku and below 20 ku， while the final digestive fragments of simulated infant stomach and intestine were mainly macromolecules， mainly above 20 ku， indicating that the digestive capacity of adult simulated digestive fluid was stronger than that of infant simulated digestive fluid. TM was easily digested by adults， while infants and young children had incomplete digestion of TM， which might be more likely to cause allergic reactions. The difference in gastrointestinal digestion between adults and infants might be due to the fact that adults had a sound digestive system， while infants had less developed gastrointestinal function and low amount of digestive enzymes