Abstract: Polyaniline(PAN) is one of the most extensively studied materials and attracts great interest from electrochemical viewpoint.However, in order to obtain the most suitable material, the physical and chemical properties of the polymer have to be modified.One of the most important methods is copolymerization.In this paper, a novel copolymer of polyaniline-poly(propylene oxide) (PAN-PPO) film was prepared by cyclic voltammetry for the first time.It was characterized with SEM and thermogravimetric analysis.In addition, the electrocatalytic activity of PAN-PPO for methanol oxidation was investigated.Results showed that under the same conditions, both redox peak currents during polymerization and conductivities of PAN-PPO were higher than those of PAN; the structure of PAN-PPO was a cross-linked network, composed of many uniform and dense nano-fibers with diameter less than 70 nm; the degradation temperature of PAN-PPO was a little lower than that of PAN.In comparison with PAN, PAN-PPO showed a high electrocatalytic activity for oxidation of methanol and the electro-oxidation reaction was controlled by the diffusion step.