Abstract: With the use of nano-titanium dioxide as bacteriostat and surface modifier improving the compatible capability between nano-TiO₂ and SEBS, the SEBS/TiO₂ nano-composites with special use were prepared and the influence of TiO₂ dosage on composite properties was also researched.The dispersed performance of nano-TiO₂ in SEBS was characterized with SEM and its bacteriostasis performance was measured with yellow index.The result showed that the tensile-strength, elongation and bacteriostasis performance of SEBS/TiO₂ nano-composites increased firstly and then reduced with increase of surface modifier.And the tensile-strength, elongation and yellow index of SEBS/TiO₂ nano-composites rose with increase of content of TiO₂.Expecially, when the amount of surface modifier and the nano-TiO₂ are 4%, the yellow index of SEBS/TiO₂ nanocomposites can reach a maxium of 27, the antibacterial properties of the material is best at this time, it also can achieve very good mechanical properties.