Objective To improve the electro-oxidation catalytic performance of Pt/ C catalyst for formic acid by adding the Pb element. Methods The PtxPb / C catalysts with different atomic ratios were prepared by an ethylene glycol-assisted NaBH4 reduction method. The structure and morphology of the catalyst were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), electrochemical performances were investigated by cyclic voltammetry. All electrochemical measurements were carried out in a conventional three-electrode electrochemical cell at 25 ℃ using cyclic voltammetry (CV) on a CHI 760B. Results The results of XRD and TEM showed that all prepared catalysts displayed typical character of Pt face center cubic phase with an average size of Pt nanoparticles at 4 nm which had an uniform dispersion on carbon support. The PtxPb / C catalysts had better electrocatalytic activity for formic acid electrocatalytic oxidation than that of JM-Pt / C. The electro-catalytic activity was affected by the atomic ratios of Pt and Pb. In addition, when the atomic ratio was 5 ： 1, the PtxPb / C catalyst showed the highest peak current den- sity (mass activity) of 2000 mA / mg Pt with better stability. Conclusion The adding of Pb atoms affects the electronic structure of Pt atoms. With the assistance of Pb to Pt, the rapid oxidation, such as CO, is promoted the intermediate products on the surface of Pt. In addition, the synergistic effect reduce the initial electric potential of catalyzing oxidation formic acid, promote formic acid directly oxidated as CO2 and H2 O, improve the peak current of catalyzing oxidation formic acid, effectively deduce the poisoning of Pt, and enhance its catalytic activity.