Cellulose acetate supported DL-alpha-tocopherol liquid surfactant membrane has been characterised by measuring membrane potentials, using sodium chloride solutions of different mean concentrations. Fixed charge density, phi (X) over bar, permselectivity, P-s, have been estimated from ionic transport numbers. Variation of membrane potential with pH and concentration of sodium chloride solution has also been examined. The data obtained have also been discussed in the light of the biological actions of DL-alpha-tocopherol.