Au-Pt/SnO2/GC　composite　electrode　was　prepared　by　self-assembling　Au-Pt　nanoparticles　on　SnO2　film,　which　was　deposited　on　actived　glassy　carbon　(GC).　Atomic　force　microscopy　(AFM)　and　scanning　electron　microscopy　(SEM)　images　revealed　that　dense　and　uniform　Au-Pt　particles　with　25-nm　diameter　were　dispersed　on　SnO2　film.　X-ray　photoelectron　spectroscopy　(XPS)　results　proved　that　there　was　an　interaction　between　Au-Pt　nanoparticles　and　SnO2　support.　Electrochemical　experiments　showed　that　Au-Pt/SnO2/GC　composite　electrode　had　a　good　electrocatalytic　activity　to　the　oxidation　of　methanol.