The purpose of this study was to examine the effect of resistant starch(RS) in hyperchlesterolemia and colon cancer. The subjects of this study was eight college women participating in the general starch diet(GSD) period for 5 days and resistant starch diet(RSD) period for 7 days. RSD contains 30g or the RS. On the last day of each program blood were collected. And for the last 3 days of each diet period, the amount of all the food consumed by the subjects and feces were collected. Food was measured to determine and compared the energy, protein and fat intakes. The amount of total cholesterol, HDL-cholesterol, LDL-cholesterol and volatile fatty acids in plasma and the amounts of bile acids in feces were measured by gas chromatography. The results obtained were as follows, Daily energy intake was higher in the RSD compared with the GSD, Protein and fat intakes were lower in the RSD compared with the compared with the GSD. Volatile fatty acid contents in plasma, the amounts of acetic acid, propionic acid and valeric acid were higher in the RSD compared with the GSD. The amounts of bile acids in feces, cholic acid, chenodeoxycholic acid and lithocholic acid were higher in the RSD compared with the GSD, But the amount of deoxycholic acid n the RSD period was significantly low. Secondary/primary ratios of bile acids was lower in the RSD compared with GSD, respectively. We speculate that , RS consumption decreases colonic mucosal proliferation as a result of the decreased formation of cytotoxic secondary bile acids. Thus, RS intakes may contribute the prevention of heart disease and colon cancer in humans. (Korean J Nutrition 33(8) : 802-812, 2000)