The administration of a fat-free, low protein diet with no B-vitamin supplement to albino rats for 3 weeks resulted in marked fatty livers. When these depleted rats suffering from fatty liver were treated with only B-vitamins for a week, liver fat and cholesterol were greatly increased. Such a type of fatty liver, however, was partly cured by administrating, besides B-vitamins, either choline or myoinositol, and almost completely by administrating both of them. A considerable delay was found in the movement of cholesterol from fatty liver to adipose tissues, when compared with that from liver cured by administration of myoinositol. This may be ascribed to an occurrence of an inhibitory mechanism on cholesterol transport in fatty liver.