The thermal conductivity of Gd2Zr2O7 films deposited on Al2O3 by RF sputtering is investigated by using the thermoreflectance method. In order to validate the thermoreflectance method, the thermal conductivity of Gd2Zr2O7 films was measured by using the 3 omega method with wide heater. The interfacial resistance at the interface between Au metal heater and Al2O3 substrate is investigated by thermoreflectance measurements of the surface of the Au heater on Al2O3 substrate. The thermal conductivity of Gd2Zr2O7 films deposited on Al2O3 by RF sputtering show the film thickness-dependence by using thermoreflectance method. It is understood with the interfacial thermal resistance between film and substrate, and the interfacial thermal resistance between Gd2Zr2O7 and Al2O3 (R-k) is 4.45 +/- 1.35 x 10(-8) m(2) KW-1. (C) 2012 Elsevier B.V. All rights reserved.