Electroactiveself-assembledmonolayers(SAMs)containingviologeugroupareformedthroughtheadsorptionofthiol-functionalizedviologencompoundCH3(CH2)9V2+(CH2)8SH,whereV2+isN,N’-diaIkylbipyridinium(i.e.aviologengroup),ontogoldelectrodesfrommethanol/watersolutionanditselectrochemicalbehaviorisinvestigatedbyAcvoltammetryandsquarewavevoltam-metry,whichhavethehighsensitivityagainstbackgroundcharging.TheviologenSAMformedisasub-monolayerandthenormalpotentialscorrespondingtothetwosuccessiveone-electrontransferprocessesoftheactivecenters(viologen)are-360mVand-750mV(vs.Ag/AgCl)in0.1mol/Lphosphatebuffersolutions(pH6.96)respectively,andthestandardelectrontransferrateconstantis9.0s-1TheelectrochemicalbehaviorofthisSAMinvarioussolutionshasbeenpreliminarilydiscussed.