The composition of passive layer of chalcopyrite was investigated by X-ray photoelectron spectroscopy（XPS）, accompanied with cyclic voltammetry（CV）. The leaching experiment shows that the extraction rates of Cu with leaching for 30 d by sterile control and microorganisms are 4.0% and 21.5%, respectively. In comparison, 3.8% and 10.5% Fe are leached by sterile control and microorganisms, respectively. The results of XPS studies suggest that Fe atoms dissolve preferentially from the chalcopyrite lattice, and disulfide（S22-）, polysulfide（Sn2-） and elemental sulfur（S0） are identified on the chalcopyrite surfaces leached by sterile control and microorganisms. Additionally, sulfate（SO42-） is detected on the chalcopyrite surfaces leached by microorganisms, and most of it probably originates from jarosite. The analysis of CV results reveals that metal-deficient sulfide（Cu1-xFe1-yS2-z, yx） and elemental sulfur（S0） passivate the surface of chalcopyrite electrode. The elemental sulfur and/or jarosite coating on the chalcopyrite surface may have impact on the leaching process; however, the disulfide, polysulfide or metal-deficient sulfide plays a more key role in the chalcopyrite leaching.
