Even though coix (Coix lachryma-jobi L. var. ma-yuen) has many physiological effects, since it has been known to cause sterility, farmers avoid using coix bran as a forage for their livestock. Therefore, as the consumption of coix increases, coix bran, which is a by product of pounding process, becomes a serious issue of environmental problem. Present study examined the physiological effects of coix bran in normal and diabetic rats for its possible use as a functional material. The effects of coix bran supplementation on plasma and hepatic lipid profile were evaluated in rats fed one of the following diet for 12 weeks : chow diet ; chow-bran diet (chow diet＋25% coix bran), high fat diet and high fat-bran diet (high fat diet＋25% coix bran). Additionally, glucose challenge and lipid metabolism in streptozotocin-diabetic rats were also examined. In normal rats, consumption of coix bran remarkably reduced body weight gain in chow or high fat diet fed rats. Additionally, consumption of coix branreduced blood TG, TC and atherogenic index (26%, 24% and 72%, respectively) in chow diet fed rats. Liver TG and cholesterol concentrations were reduced (43% and 49%, respectively) in high fat fed rats by coix bran supplementation. In diabetic rats, fasting blood glucose level was reduced about 25% by coix bran consumption. Also, glucose challenge pattern was improved and resembled normal pattern : it reaches to peak 15~30 minutes after glucose administration and get back to fasting blood glucose level after 90 minutes. Plasma concentrations of TG were elevated in diabetic rats and were reduced to normal level by coix bran supplementation. Liver TG and cholesterol concentrations were also elevated in diabetic rats and reduced to normal level by consumption of coix bran. These results suggest that coix bran may have beneficial effects on blood lipid and glucose level in normal and diabetic rats.