Abstract: Nonmetallic ions（S） doped TiO₂ nanomaterials were prepared by sol-gel technique using TiCl₃ and calcined at 500℃ for 1h.Structural properties of S-doped TiO₂ were characterized by XRD,FT-IR,UV-vis,ESEM,Zeta potential,XRF,TPD.The results show that doping sulfur is favorable to phase transformation from anatase to rutile.The Sulfur is in the primary form of S⁴⁺ with lower concentration（2at%）,while concentration of dopant is up to 25at%,some O^2- anions in the lattice are substituted by S^2-.For the difference of electronegativity between oxygen and sulfur,the density of Ti³⁺ or Ti⁴⁺ electronic cloud on the surface is increased.Further,it improved activity of oxygen adsorption and redundant electrons on the surface are transferred to adsorptive oxygen.At last,the oxygen sensitivity for an oxygen sensor based on S/TiO₂ is enhanced.Adsorptive oxygen on the surface of S/TiO₂ is desorbed in oxygen molecule（≤ 550℃）,but in SO₂ at higher temperature（≥ 600℃）.