The effect of activity on potential of interfacial tension maximum in aqueous solutions of I−, Br−, and Cl− is investigated for gold electrodes. It is seen that the potential decreases with ion concentration at a rate of −0.1V/decade in activity for I− and Br−. Electrocapillary‐type curves for is found to almost coincide with that for . Change in interfacial tension for I− and Br− is of the same magnitude in methanol solution as in aqueous solution.