Periodic electrochemical oscillation was observed in a certain potential region when electrodeposition of zinc was performed at the interface between n-butyl acetate and a ZnSO₄ aqueous solution. It was found that the electrochemical oscillation takes place synchronously with the periodic motion of a meniscus formed on the perimeter of a working electrode at the interface. We concluded that the motion of the interface is associated with the change in the interfacial tension caused by consumption and restoration of zinc ions in the aqueous solution around the working electrode.