The　nano-azed　TiO2　photocatalysts　were　prepared　by　sol-gel　method　and　characterized　by　FTIR　spectroscopy,　FT-Raman　spectroscopy　and　diffuse　reflectance　spectroscopy(DRS).　Photocatalytic　degradation　of　oleic　acid　over　the　TiO2　catalysts　was　investigated.　The　result　showed　that　calcination　temperature　has　strong　effect　on　crystal　structure,　energy　band　structure,　optical　adsorption　and　photocatalytic　activity　of　the　TiO2　catalysts.　It　was　found　that　the　TiO2　photccatalyst　calcined　at　400°C　has　the　best　apparent　optical　adsorption,　the　biggest　band　edge　position　and　the　highest　photoactivity.　The　effect　of　calcination　temperature　on　photocatalytic　activity　of　TiO2　catalysts　has　been　ascribed　to　the　changes　in　structure　and　optical　property　of　catalyst　such　as　crystal　size,　content　of　rutile,　residual　NO-3,　and　band-edge　position　of　light　adsorption.