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High quality Tl 2 Ba 2 CaCu 2 O 8 (Tl-2212) superconducting thin films were fabricated on 2 inch double-sided CeO 2 buffered r-cut sapphire substrates. The metal cerium target was used as the sputtering source to deposit the CeO 2 buffer layer by the RF magnetron reactive sputtering technique, and the inter-diffusion of chemical elements between the CeO 2 layer and the substrate was studied by XPS depth profiling. The crack-free Tl-2212 films with dense crystal structure and smooth morphology were homogeneous over the whole area of the film. The XRD measurement confirmed the purity of the Tl-2212 phase and the texture with c axis perpendicular to the surface of the CeO 2 buffered sapphire substrate. The electrical and magnetic measurements on the Tl-2212 films showed that the transition temperature T c was around 106 K, and the critical current densities J c (77 K, 0 T) for both side films were 2.9 ± 0.1 MA cm −2 and 1.6 ± 0.2 MA cm −2 , respectively. The microwave surface resistance R s on one side film was about 390 μ and on the other side 450 μ at 10 GHz and 77 K.