Abstract: Photo catalytic degradation experiments of soluble dichloroethane in water were conducted using fixed nanometer TiO 2 as photo catalyst under ultraviolet light. The results reveal that the degradation process is a pseudo first order reaction kinatically. The kinetic equations and parameters show that the degradation efficiencies of dichloroethane in water are influenced by the initial concentrations of dichloroethane, amounts of photo catalyst and illumination intensities. The rate constant of photo catalytic degradation of dichloroethane increases with the increasing of the initial concentration, the illumination intensities, and the doses of photo catalyst.