Abstract: To study the effect of copper ion on the membrane electrode assembly (MEA) of a proton exchange membrane fuel cell (PEMFC) and the recovery method of performance of PEMFC with the MEA that was eroded by the copper ion, the contamination on the surface of the MEA was examined by the X-Ray Diffraction (XRD) and the boiling method to renew the performance of MEA was performed.In experiments, it is found that the metal polar plates were eroded because of some flaws on gold film of the plates, and the copper ion dramatically influenced the performance of the MEA.The experimental results indicate that the method of boiling MEA in 0.2 m diluted sulfuric acid could take off copper ion from MEA surface and renew the performance of MEA.The effect of the method for separated membrane electrode assembly is better than that for hot-pressed sandwiched membrane electrode assembly because the hydrophobicity of carbon paper could be poorer after the carbon paper is boiled in diluted sulfuric acid.