Vapor-liquid equilibria of aqueous ethanol solution containing minor components (glycerin and diols) were measured at atmospheric pressure to obtain basic data of the minor component behavior in distillation. The diols were ethyleneglycol, diethyleneglycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol and 1,6-hexanediol. The vapor-liquid equilibrium ratio of glycerin in aqueous ethanol solution was 10(-3) to 10(-2), depending upon the ethanol concentration. The dependence of vapor-liquid equilibrium ratio of diols on the ethanol concentration was quite different from those of other minor components which are found in Shochu mash.