An experiment was performed to determine if buckwheat intake would improve insulin sensitivity in in normal healthy ras and steptozoticin-induced diabetic Sprague-Dauley rats. For four weeks, rats were fed either corn starch as a cotnrol diet or buckwheat as an experimental diet. As a result, the insulin sensitivity and plasma glucose levels in normal rats were not significantly affected by buckwheat fedding. The insulin sensitivity was lower in diabetic rats than in normal rats(p<0.05). Buckwheat tends to decrease the final plasma glucose level and increase insulin sensitivity in diabetic rats, but there was no sifnificant difference. Another five-week experiment was conducted to determine protein digestibility and protein utility in normal healty rats ad streptozotocin-induced diabetic rats on a control diet or buckwheat diet. The diet composition in this experiment was the same as the preceeding experiment. In the cotnrol diet groups, the protein digestibility in diabetic rats was significantly lower than that in normal rats(p<0.05). Buckwheat reduced protein digestibility in both normal and disbetic rats(p<0.05). Interestingly, in buckwheat diet groups, protei digestibility in diabetic rats was similar to that in normal rats. Protein utility was significantly lower indiabetic rats than in normal rats. This phenomenon was observed as early as the first week of the feeding period. However, protein utility was not sifnificanlty altered in both normal and diabetic rats by buckwheat feeding. It follows that decreased protein digestibility and utility in diabetic rts are not further aggravated by buckwheat feeding, suggesting that buckwheat can be a feasible supplement food for the diabetic therapeutic diet.