Rats were adapted to diets containing 10% cellulose,10% sodium alginate and fiber-free diet for 5 weeks. Following a 14 hour fasting, rats were fed 5g of a test meal that provided 50% energy from fat, then killed at 4 hour postprandially. Plasma and lipoprotein fraction-cholesterol levels were lower in sodium alginate-fed animals than in rats fed other diets. Plasma TG did not differ among diet treatments. Increase in TG content of HDL fraction occurred in dietary fiber groups. Intestinal apolipoprotein B level and lipase activity were lower in sodium alginate-fed group than in other dietary groups. These results suggest that chronic consumption of sodium alginate affects plasma cholesterol level as in the case of fiber supplemetation, but is less likely to modify the acute Plasma TG response to high fat meal than if a fiber supplement is incorporated into the meal.