Each twenty male and female young rats (Donryu) were divided into five groups. Four groups of each sex were fed fat-free diet with different carbohydrates; cornstarch, glucose, sucrose, or fructose. The remaining one group of each sex was fed a commercial diet. After rearing for one month, hemoglobin content, level of blood sugar, weight of organs, and content and composition of lipids in serum and liver were measured. (1) Among the female carbohydrate-groups, the variation in the weight of organs was significantly large only in carcass and adrenals. Contents of hepatic lipids were similar among the carbohydrate-groups. The lowest content of serum lipids was found in the glucose group. (2) In the male, significant variations were found in the weights of carcass, spleen and kidneys. The highest content of hepatic lipids was in the starch group, but the highest content of serum lipids was in the fructose group. (3) The present experimental conditions were particular in that fat and fatty acids were excluded from diet in comparison with similar experiments reported, and the sex-difference in the response of rats to different kinds of carbohydrates found in the present study was similar to that being already noted.