Optical properties, surface roughness and packing density of TiO2 thin films obliquely deposited on K9 glass by electron beam evaporation are investigated. The surface roughness of TiO2 thin films with different incident deposition angles are compared. The experimental results show that the transmittance increases and transmittance peak shifts to short wavelength with increasing incident deposition angle, and that the packing density of TiO2 thin films decrease from 0.801 to 0.341 with incident deposition angle increasing from 0° to 75°. The surface roughness of TiO2 thin films increases with increasing incident deposition angle, and at 75°, it is slightly higher than the surface roughness of K9 substrate. When the incident deposition angle is constant, TiO2 thin films surface roughness decreases with the increase of film thickness.