In order to study the properties of supporting Pt catalysts for methanol oxidation,carbon-nanotubes are used by electrochemical deposition method. Different deposition turns,different cyclic voltammetry scanning speeds and processing time with ascorbic acid are investigated in this paper. The micrographs of Pt / CNTs catalysts are characterized by scanning electron microscopy,the electro-catalytic properties of Pt / CNTs catalysts for methanol oxidation are investigated by cycle voltammetry and chronoamperometry. The results show that the size of platinum will be greater with the faster scanning speed. After dissolution in ascorbic acid,Pt nanoparticles disperse uniformly. The obtained Pt / CNTs catalysts show a high electro-catalytic activity and stability. Different order turns, different cyclic voltammetry scanning speeds and processing time with ascorbic acid are investigated in this paper. The micrographs of Pt / CNTs catalysts are characterized by scanning electron microscopy, the electro-catalytic properties of Pt / CNTs catalysts for methanol oxidation are investigated by cycle voltammetry and chronoamperometry. The results show that the size of platinum will be greater with the faster scanning speed. After dissolution in ascorbic acid, Pt nanoparticles disperse uniformly. The obtained Pt / CNTs catalysts show a high electro-catalytic activity and stability.