Chalcopyrite oxidation rates were examined under various conditions in the presence of Leptospirillum ferriphilum,in which the effects of different pulp content,inoculation amount,extal addition of Fe3+ and initial pH value were studied.The bioleaching residues were investigated by X-ray diffractograms(XRD),scanning electron microscopy(SEM)and energy dispersion spectrum(EDS)analysis.The results show that low pulp concentration increases the leaching rate of copper,and extal addition of Fe3+ is also beneficial to leaching chalcopyrite.The changes of inoculation amount and initial pH fiom 1.6to 2.5 have a little effect on the final leaching rate.The results also imply that Fe3+ ions are important for bioleaching of chalcopyrite.At the end of bioleaching,jarosite and sulfur are observed on the surface of chalcopyrite residues by using XRD,SEM and EDS.With the passivation layer formed by jarosite and sulfur,the continuous copper extraction is effectively blocked.