Abstract: High frequency combustion infrared-adsorption spectroscopy was applied to the determination of sulfur in gibbsite-type bauxite.The bauxite sample was pretreated by ignition under 750 ℃ for 20 min.1.4 g of pure iron and 1.5 g of mixed flux (tungsten and tin) were added.Linearity range of sulfur was found in the range of 0.31%-1.0%.Values of recovery found by standard addition method were in the range of 99.1%-101%,and values of RSD′s (n=7) in the range of 0.50%-0.85%.