Abstract: Double bonds were introduced onto the surface of nano-TiO2 particles by treating it with a coupling agent,vinyl tri-tert-butyl peroxy silane (AC-70),then polyacrylonitrile (PAN) was found as :reaction time 5h,the reaction temperature75℃, the monomer concentration is 6, the BPO concentration 1.0%. Infrared spectra (FTIR) and XPS analysis showed that PAN was grated onto the surface of nano-TiO2. Hydrophilic-oleophilic and the contact angle test showed that the surface of nano-TiO2 changed from hydrophilic to lipophilic, the contact angle increased. The scanning electron microscopy (SEM) showed that the agglomeration of nanoparticles significantly reduced. Finally, ultraviolet absorption(UV-V) analysis showed that nano-TiO2-g-PAN particles possessed an excellent ultraviolet absorbing ability.