Root of burdock contains high amounts of dietary fibers and polyphenols. To improve the functional properties, the root was fermented with Aspergillus awamori. Effect of the fermented burdock on alloxan-induced mouse diabetes was examined. A diet containing the 5% fermented burdock powers was prepared to examine effect of the burdock diet on alloxan-induced mouse diabetes. Mice fed the burdock diet and the control diet for 14 weeks. Then, alloxan (200 mg/kg of body weight) was administrated to each mouse. After 5 days from the administration, blood glucose assay and glucose tolerance test were carried out. Incidence of hyperglycemia decreased and the glucose metabolism was improved when mice fed the burdock diet. Insulin, C-peptide, biomarkers of oxidative stress in plasma and apoptosis in pancreas were examined and compared to those obtained from mice fed the control diet. It is deduced that alloxan-induced diabetes is caused to lower insulin concentration. The fermented-burdock diet improves the diabetes and prevents apoptosis in the pancreas.