Rhodotorula sp. RS1 isolated from acidic oil-tea fields is a high Al-tolerant microorganism. In this study, its Al-tolerant characteristic was studied. Results showed that the growth of RS1 colony was inhibited under the treatment of 50-200 mmol/L Al3+; however, Al toxicity did not obviously influence the cell morphology. RS1 showed higher tolerant ability for Al2(SO4)3 than AlCl3, and this high Al-tolerant ability was not induced by Al3+. Under the treatment of highly Al toxicity, RS1 could increase protein content, and protein thiols may play an important role in high tolerance of RS1 to Al.