The purpose of this study was to investigate the effects of dietary xylooligosaccharide on lipid levels of serum in rats fed high cholesterol diet. Male Sprage-Dawley rats weiging 100$pm$10g were randomly assigned to groups of two normal(N, N+10X) and four high cholesterol diets which contained 1%(w/w) cholesterol. High cholesterol diet groups were classified to xylooligosaccharide free diet (C group), 5% xylooligosaccharide diet(C+5X group), 10% xylooligosaccharide diet(C+10X group) and 15% xylooligosaccharide diet(C+15X group) according to the level of dietary xylooligosaccharide supplementation. These experimental diets were fed ad libidum for 4 weeks. The weight gain of high cholesterol diet group were significantly increased more than that of normal group, but those of 10% and 15% dietary xylooligosaccharide groups were significantly decreased more than that of high cholesterol diet(C)group. The higher content of xylooligosaccharide, the more food intake was increased. The food efficiencies of 10%, 15% cholesterol diet groups were lower than that of high cholesterol diet(C)group. The levels of serum triglyceride(TG) and total cholestoral were significantly high in cholesterol diet groups compared with normal diet group but were decreased in groups fed 5% and 10% dietary xylooligosaccharide. Especially, the lowest level showed in group fed high cholesterol diet containing 10% xylooligosacchride. High cholesterol diet group containing 10% xylooligosaccharide increased HDL-cholesterol level and then decreased LDL-cholesterol level and atherogenic index compared with other groups. The level of TBARS(thiobarbituric acid reactive substances) in serum was decreased in rat group fed xylooligosaccharide in high cholesterol diet. The higher content of xylooligosacchride, the more gastrointestinal transit time was decreased. The results indicate that dietary xylooligosaccharide can improve status of TG and total cholesterol and repress lipid peroxidation in serum lipid at hypercholesterolemia induced by high cholesterol diet.