The　PtxSn/C　(x　=　1,　2,　2.5,　3,　4)　anodic　catalysts　for　direct　ethanol　fuel　cell　(DEFC)　have　been　prepared　by　an　improved　microemulsion　method.　Ethylene　glycol　is　used　as　cosurfactant,　and　metal　precursors　are　dissolved　in　it　beforehand　to　prevent　the　hydrolysis　of　metal　precursors.　The　composition,　particle　size　and　structure　of　these　catalysts　are　characterized　by　energy　dispersive　X-ray　spectrum　(EDX),　transmission　electron　microscope　(TEM)　and　X-ray　diffraction　(XRD).　The　results　show　that　the　synthesized　Pt　3Sn/C　catalyst　has　part　of　Pt　and　Sn　alloying.　The　average　diameter　is　about　2.9　nm,　and　has　a　narrow　size　distribution　and　a　good　dispersivity.　The　electrochemical　experiments　indicate　that　the　Pt3Sn/C　catalyst　prepared　in　the　neutral　microemulsion　has　superior　catalytic　activity　for　ethanol　oxidation.　The　PtxSn/C　nanoparticle　formation　in　the　improved　microemulsion　is　also　discussed.　©　2010　Elsevier　B.V.　All　rights　reserved.