This study was designed to observe the effects of the feeding of Hijikia fusiforme(Harvey) Okamura juice extract on the improvement of lipids in the serum of cholesterol-supplemented diet induced dietary hyperlipidemic rats fed experimental diets for 4 weeks. Concentration of total cholesterol and LDL-choloesterol in serum was significantly lower in the Hijikia fusiforme juice extract group than in the cholestero diet group. Concentration of HDL-cholesterol in serum was higher in the Hijikia fusiforme juice extract group than the cholesterol supplemented diet group. Those in the Hijikia fusiforme juice extract group were higher than those in the cholesterol diet group. In the ration of HDL-cholesterol concentration to total cholesterol concentration, Hijikia fusiforme juice extract administration group was higher percentage than the other groups. Atherosclerotic index was lower in the Hijikia fusiforme juice extract group than in the cholesterol diet group. Concentration of free cholesterol and cholesteryl ester in serum was rather lower in the Hijikia fusiforme juice extract group than the other groups. Triglyceride concentration in serum was significantly lower in the Hijikia fusiforme juice extract group than in the cholesterol diet group. Concentration of phospholipid in serum was more decreased in the Hijikia fusiforme juice extract group than in the cholesterol diet group. The activities of aspartate aminotransferase and alanine aminotransferase in serum were rather lower in the Hijikia fusiforme juice extract group than the cholesterol supplemented diet group. From the avove research, the Hijikia fusiforme juice extracts were effective on the improvement of the lipid compositions in serum of high fat diet induced dietary hyperlipidemic rats.