Catalytic oxidation is a potential way to disinfect air through a air-condition system. We find that the SARS coronavirus, bacteria and yeast are completely inactivated in 5 min on Ag catalyst surface and in 20 min on Cu catalyst surface at room temperature in air. Scanning electron microscopy (SEM) images show that the yeast cells are dramatically destructed on the Ag/Al 2O3 and Cu/Al2O3 surfaces, which indicates that the inactivation is caused by catalytic oxidation rather than by toxicity of heavy metals.