The influence of fat level and dietary fiber on serum and liver lipid concentration of the rat was investigated. Groups of rats were fed respectively 3%, 5%, 20% fat containing and free fiber diet until 5th week. From 5th week to 9th week high fat diet groups of rates were devided high fat diet group, high fat pectin supplemented diet group and high fat celulose supplemented diet group. Pectin and cellulose at 10% was supplemented to high fat diets. After rats were fed for 9 weeks, all rats were sacrificed to collect the liver and blood samples by heart puncture. Serum and liver lipids were determined on all rats and compared the histochemical lipid staining method with the biochemical analysis of serum and liver lipids. A high fat diet caused increased level of the total lipids, total cholesterol and free cholesterol contents in the liver and the serum. Rats fed pectin reduced body weight, werum lipid and liver lipid but cellulose had no effect to reduce serum and liver lipid concentration. These results indicate that dietary fat level led to changes in the lipid metabolism of rats and that pectin was more effective in lowering serum and liver lipid than cellulose.