This study was conducted to investigate the effect of fructooligosaccharide on intestinal flora, lipid metabolism and immune response. Thirty two male rats of Sprague-Dawley strain were divided into two groups according to body weight. Each group was fed the diet containing 2% cholesterol or the normal diet, respectively for 4 weeks. Each group was again divided into two sub-groups and they were fed with the diet containing 5% of sucrose and fructooligosaccharide, respectively for 8 weeks. The number of bifidobacteria slight increased, but not significantly, in oligosaccharide groups. Plasma total lipid concentration in cholesterol group was signficantly increased compared to the value in normal group. Dietary oligosaccharide decreased plasma total lipid concentration and triglyceride concentrations in normal group, but not in cholesterol group. Fecal lipid excretion was higher in cholesterol group than in normal group. Fecal cholesterol concentration in cholesterol-oligosaccharide group was significantly increased compared to other groups. Cholesterol had slight effects on TBARS and the immune status, but dietary oligosaccharide had no effects on these variables. The results in this study suggest that dietary oligosaccharide had no effect on serum and liver profiles of rats fed high cholesterol diet but increases the fecal cholesterol excretion.