The electrochemical and spectral properties of four α,α′-dioxoketene cyclic dithioacetals were studied.All these compounds have only one quasi-reversible peak at around-1.4—-1.6 V on platinum microelectrode.The self-assembled monolayer film of these compounds was prepared on gold electrode and investigated by the electrochemical impedance spectroscopy(EIS) and X-ray photoelectron spectroscopy(XPS).The cyclic voltammogram peak potential and semicircle diameter were influenced by the number of methylenes and the substituting groups at one point of a ketone.