Abstract: A high-sucrose diet induces insulin resistance and dyslipidemia in normal rats. The purpose of the present study was to investigate the effects of a high-sucrose diet on glycolipid metabolism in Spontaneously Diabetic Torii (SDT) rats, a genetic model of nonobese type 2 diabetes. Male SDT rats were fed with a high-sucrose (68% of energy) diet from 8-24 weeks of age. SDT rats fed a high-sucrose diet showed hypercholesterolemia, hyperinsulinemia and hyperleptinemia but the body weight and the serum triglyceride level were not increased. Unexpectedly in SDT rats fed a high-sucrose diet, we observed a suppress of the incidence of diabetes mellitus. In computed tomography analysis, SDT rats fed a high-sucrose diet showed an increase of visceral or subcutaneous fat tissue weight. In pathological analyses, slight or mild fatty liver was observed by high-sucrose feeding. A high-sucrose diet in SDT rats induced dyslipidemia, insulin resistance and fat storage but not development of diabetes. High sucrose-fed diabetic rats are considered to be useful for further elucidation of complex mechanisms in glycolipid metabolic abnormality.