Abstract: β-Casomorphin-7 (β-CM-7) is a milk biological active peptide. The present study is aimed to investigate the protective effects of β-CM-7, against oxidative stress in pancreas of streptozotocin-induced diabetic rats by assaying malondialdehyde (MDA), nitric oxide (NO) level, the activity of enzymatic antioxidants such as superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px), and NF-κB, inducible nitric oxide synthase (iNOS) gene expression. A significant increase in the level of oxidative stress was observed in pancreas of the diabetic rats when compared to control rats. After 15 d oral administration of β-CM-7 (7.5 × 10−8mol/d), the pancreas MDA level was markedly reduced. Oral administration of β-CM-7 to diabetic rats showed an obviously increase in the activity of catalase in pancreas, oral administration of β-CM-7 to the diabetic group of rats also showed a reduction of NF-κB and iNOS gene expression in pancreas. The elevated pancreas NO level was markedly reduced by the oral administration of β-CM-7. Thus, the results of the present study suggest that β-CM-7 may cause protective effects such as pronounced decreasing in oxidative stress and inhibiting NF-κB-iNOS-NO signal pathway in pancreas of diabetes rats.