This study showed the effect of fermented milk on the cholesterol level of Korean. 130 persons among the teachers of elementary, middle and high schools, professors and graduate school students were divided into two groups according to their cholesterol level and provided with fermented milk 300 $mell$ dairly from Sep.25 to No. V3. They were given blood test at 20 days and 40 days after drinking fermented milk, and surveyed about their ordinary life style and the change of fecal condition. Cholesterol, LDL and the ratio of LDL and HDL in blood were significantly decreased in both high cholesterol group and normal group while HDL cholesterol was notably increased. TG showed slightly tendency of decrease in normal group while no changed in high group. There is no significant change in cholesterol level after drinking fermented milk among groups which are divided by factors of dringking, smoking, caffeine, B.M.I. and family history. The research also showed that drinking fermented milk improved the fecal frequency and fecal condition.