Cyclic voltammetry and in situ electrochemical FTIR spectroscopy techniques have been combined to study the methanol electro-oxidation on polypyrrole modified by platinum（nm-Pt/PPy）.The nm-Pt/PPy shows good electrocatalytic activity for methanol electro-oxidation，and the final product CO2 can be observed at 1000mV.However，CO poisoning of Pt particles can’t be avoided despite the presence of polypyrrole film.At low potentials，the linearly absorbed CO and the bridge-bonded CO form on the nm-Pt/PPy，respectively.With the potential increasing，there is only the linearly absorbed CO.At high potentials，the PPy is overoxidized and the electrocatalytic activity of nm-Pt/PPy is decreased.