¹Department of Nutrition, School of Tourism cooking & Food science and engineering, Yangzhou University, Yan 225000, CHINA DOI : 10.9775/kvfd.2018.21628 The immune deficiency caused by aging deserves attention, especially the weakening of intestinal mucosal immunity. The effect of β-casomorphin-7 on intestinal mucosal immunity was investigated in aged mice. Mice were treated without or with different doses of β-casomorphin-7 for 30 days. Histopathological studies showed the tissue protective role of β-casomorphin-7 in aged mice. Low-dose group could significantly increase the level of IL-2 and TNF-α in intestinal mucosa. A significant increase in the level of SIgA was observed in medium- and high-dose groups. The low and medium dose groups could significantly increase the activity of SOD in small intestine mucosa. All dose groups significantly reduced the levels of MDA. The results suggest that β-casomorphin-7 could improve intestinal mucosal immune decline which is induced by aging The mechanisms for the regulating effects were likely through balancing the cytokine level and controlling the oxidative stress. Keywords : β-casomorphin-7, Aging intestinal mucosal immune cytokine, Oxidative stress