To study the high-fat-diet induced rat obesity and the of fect of endurance training on the body fat content of obese rats, we randomly divided 66 male weanling SD rats into control(16 rats) and high fat diet group(50 rats). After 10 weeks, we chose diet-induced obese rats(DIO, 26 rats) and divided them into endurance training group(DIO-T, 8 rats) and DIO groups(DIO, 18 rats) randomly. Aner 8 weeks, endurance training, all rats were killed. The results showed that nosignificant difference was found between groups in body weight, the feed efficiency of DIO groups was higher than control groups, tke carass fat con tent of DIO-T group was significantlylower than DIO group, and plasma insulin concentration of DIO group was higher than control and DIO-T groups. It was suggested that rats' obesity was induced obesity by high fat diet, dietary obesity had relation to higher eding efficiency and hyperinsulinemia. Endurance training can effectively reduce the body fat content of high-fat-diet induced obese rats by improving its hyper-insulinemia. Plasma TCH and TG of all rats had no significant difference.