Gallium-doped zinc oxide (GZO) films have been grown on polycarbonate (PC) substrates with and without ZnO buffer layers by radio frequency (r.f.) magnetron sputtering at room temperature. The optimization of growth parameters (sputtering power, sputtering pressure, sputtering time, oxygen partial pressure ratio) on ZnO buffer layers with multiple qualities based on the orthogonal array has been studied. The optimal parameter of the ZnO buffer layer could be obtained according to the range analysis method. The lowest electrical resistivity of GZO/ZnO/PC films is about 5.21 x 10(-4) Omega cm, and the transmittance in the visible range is about 80%. using air as reference. The good transparency-conducting property and the room-temperature depositon on polymeric substrates enable GZO films to be widely used in flexible optoelectronic devices such as thin film solar cells. (C) 2010 Elsevier B.V. All rights reserved.