Abstract: The influence of heat treatment in air and NH₃ atmosphere on the photocatalysis of nanometer rutile TiO₂ were studied. The samples were characterized by UV spectrophotometry, X-ray diffraction （XRD） and X-ray photoelectron spectroscopy（XPS）. The results show that the photocatalytic activity of samples after heat treatment at 525℃ in NH₃ and at 600℃ in air are improved by 30% and 60%, compared to that of original sample under ultraviolet and visible light irradiation. The samples keep rutile crystal structure and size unchanged after heat treatment. Slight amount of nitrogen is detected in NH₃ -treated TiO₂.