Two sphalerite samples with different iron/sulphur (Fe/S) ratios, Shuikousan ore (Fe/S 0.2) and Dachang ore (Fe/S 0.52), were processed using three microbial species,Leptospirillum ferriphilum,Acidithiobacillus ferrooxidansandAcidithiobacillus caldus.Following 20 days of bioleaching in shake flask cultures, a higher zinc (Zn) extraction (96%) was achieved with Shuikousan ore than with Dachange ore (72%). The extraction efficiency increased when elemental S was added to Dachang ore to attain the same Fe/S ratio as that for Shuikousan ore. Following the addition of S, the redox potential, pH and total dissolved Fe for Dachang ore demonstrated similar behaviors to those of Shuikousan ore.Acidithiobacillus caldusandL. ferriphilumbecame the dominant species during the bioleaching of sphalerite with a high Fe/S ratio. In contrast, the dominant species wereA. ferrooxidansandA. caldusduring the bioleaching of sphalerite with a low Fe/S ratio. These results show that the Fe/S ratio has a significant influence on the bioleaching behavior of sphalerite and the composition of the microbial community.