Vapor-liquid equilibria of aqueous ethanol solutions containing a minute amount of acetaldehyde, isobutyraldehyde, ethyl acetate and isoamyl acetate were measured by use of an Othmer-type still at 12.7, 25.3 and 101.3 kPa. The equilibrium ratio curves of the minor components iisobutyraldehyde, ethyl acetate and isoamyl acetatej at each pressure are presented by a function of the concentration of ethanol. However, the equilibrium ratio curves of the minor component (acetaldehyde) could not be obtained, because the data is slightly scatted.