This study was conducted to find out the effect of fermented milk on lowering of serum and liver cholesterol in high diet. Sprague-Dawley male rats of 200g initial average weight were assigned to four experimental group : (1) high fat diet + milk (2) high fat diet + bifidobacteria (3) high fat diet + microcapsulated bifidobacteria (4) high fat diet + fermented milk by bifidobacteria. Milk, bifidobacteria, microcapsulated bifidobacteria and fermented milk by bifidobacteria were given 2ml per day. According to the result, there was lowering effect of serum and liver total cholesterol in fermented milk feeding group, Serum LDL-cholesterol was also low tendency in fermented milk by bifidobacteria feeding group. Accordingly, it was confirmed that the material that caused hypocholesteremic effect was not the bifidobacteria itself in fermented milk but the metabolic material produced in the fermentation, and it inhibited cholesterol synthesis in liver.