ZnGa2O4:Mn and CaTiO3:Pr thin-film phosphors which emit green and red light, respectively, were deposited on ZnO/ITO/glass and ITO/glass substrates by a rf reactive magnetron-sputtering method. To improve photo- and cathodoluminescent properties of the thin-film phosphors, ZnO buffer layers were deposited between the thin-film phosphor and the ITO-coated glass substrate. A transparent c-axis preferentially oriented ZnO thin-film buffer layer could be obtained on the ITO film, while ITO had an amorphous-like structure. ZnGa2O4:Mn and CaTiO3:Pr thin-film phosphors were used to evaluate the effects of the ZnO buffer layer. The crystal structures of thin-film phosphors deposited on ZnO/ITO/glass substrates were developed better than those on ITO/glass, consequently. the former showed photo-and cathodoluminescent intensity at least twice as high as the latter.