This study was performed to investigate the effect of rice bran dietary fiber powder on serum lipid levels, bowel function, and mineral absorption in rats. Four weeks old male Sprague Dawley rats(SD rat) were divided into four groups : control group fed 5% cellulose as a fiber source, RB10 fed 5% of cellulose and 10% of rice bran dietary fiber powder, RB20 and RB30. The animals were fed the experimental diets for 4 weeks. Serum lipid levels were not significantly different among the groups. But, fecal total cholesterol(TC), triglycerides(TG), and high density lipoprotein cholesterol(HDL-c) excretion increased in the RB30 group. Fecal weight and fecal water content were higher in the rice bran added groups than those in the control group. Transit time was significantly shorter in the rice bran fiber-added groups than that in the control. Weight of the stomach and large intestine in the RB20 and RB30 groups were significantly greater than those in the other groups. Absorption rates of Ca, Mg, P, and Zn decreased significantly in the RB30 group compared to those in the other groups. A high amount of rice bran increased fecal lipids, including TC, TG and HDL-c. Rice bran increased fecal weight and fecal water content and shortened gastrointestinal transit time. However, a high level of rice bran diet decreased mineral absorption rates.