The　Pt/thioglycolic　acid/GC　composite　electrode　was　prepared　by　self-assembling　Pt　nanoparticles　on　GC　modified　with　thioglycolic　acid.　The　composite　electrode　was　characterized　by　SEM　and　cyclic　voltograme　method.　The　results　show　that　the　compact　absorbing　layer　was　formed　because　of　thioglycolic　characteristic　absorb　on　the　surface　of　GC　electrode.　The　composite　electrode,　which　had　been　self-assembled　for　19　h,　in　the　2.5　mmol/L　H2PtCl6　and　1.0　mmol/L　PVP　mixture　solution,　gave　a　good　electrocatalytic　oxidation　of　methanol　in　acidic　system.