We prepared a series of substrates with various roughness, on which we deposited the thin films of c-axis oriented La2-xBa xCuO4 copper oxide superconductor with x fixed at the optimum doping 0.15 under common and reproducible conditions using pulsed laser deposition. By measuring the substrate surface roughness on the terrace with atomic force microscopy and the superconducting transition temperature T c with the in-plane resistivity measurement, we investigated the correlation between Tc and terrace roughness on the substrate surface. We observed a tendency that those deposited on substrates with smoother terrace show higher Tc. Possible reasons of this correlation is discussed. © 2005 The Surface Science Society of Japan.