Polyaniline (PANI)/multi-walled carbon nanotubes (MWNTs) composite films were fabricated by electropolymerization of aniline containing well-dissolved MWNTs. The films can be used as catalyst supports for electro-oxidation of methanol. Cyclic voltammogram and Chronoamperogram results show that platinum particles deposited on PANI/MWNT composite films exhibit higher electrocatalytic activity towards methanol oxidation than that deposited on pure PANI films. The porous structure and electrical conductivity of PANI films has been significantly changed by introduction of MWNTs, higher surface areas of PANI/MWNT composites has been achieved therefore. It favors for platinum particles to be highly dispersed on the PANI/MWNT composite films and the better electrocatalytic activity of Pt/PANI/MWNT electrode is induced consequently.