To clarify the therapeutic effects of several traditional Chinese medicines to improve disorders of carbohydrate, lipid and mineral metabolism, spontaneously diabetic rats (WBN/Kob) were treated with Vit. D2, 1 x 10(5) I.U./kg b.w./day, for 4 days, and then fed a hyperlipidemic diet containing traditional Chinese medicines for 6 weeks. The following results were obtained: 1) In the diabetic rats, the 3 traditional Chinese medicines further decreased the blood glucose level at 120 min after glucose loading in the glucose tolerance test. 2) The drugs increased the inorganic phosphate in the liver and normalized mineral metabolic disorder. 3) Hachimi-zio-gan decreased the cholesterol content in the kidney, and Sho-saiko-to decreased the cholesterol content in the elastin fraction (elastin-cholesterol) of the kidney. Such experimental results suggest that traditional Chinese medicines may be effective against the pathological conditions of diabetes mellitus that involve disorders of lipid and mineral metabolism.