Abstract: The high-sulfur bauxite in Wenshan of Yunnan is sedimentary bauxite and its high ratio of Al₂O₃ to SiO₂(A/S) can meet the requirements of alumina production by Bayer process. The high sulfur content in ores of 1% to 18%, however, is unfavorable as sulfur will cause pipe scale, increase of alkaline consumption, slowing down of seed precipitation and sacrifice of alumina quality. Consequently, desulfurization is necessary for the utilization of this kind of bauxite. The content of sulfur, Al₂O₃ and SiO₂ in the sample for the tests is 6.8%, 49.39% and 7.87%, respectively, and the A/S is 6.27. Desulfurization of high-sulfur bauxite by flotation was carried out by using a new activator and combined collectors. Acid-free activation and intensive pyrite recovery were achieved. The technical indicators of the desulfurization by flotation are satisfying. The content of sulfur, Al₂O₃ and SiO₂ inalumina concentrate is 0.43%, 56.65% and 8.56%, respectively. The recovery of Al₂O₃ is 92.71% and the A/S isincreased slightly to 6.62. The sulfur content and recovery in sulfur concentrate is 34.06% and 94.88% respectively. This study serves as a reference for the efficient utilization of this kind of high-sulfur bauxite.