Epitaxial CeO 2 (35 nm) buffer layers were deposited on MgO(001) single crystal substrates by an electron beam gun for preparation of YBCO films by coating pyrolysis (CP). When the substrate temperature was higher than 660 o C, the CeO 2 layer exhibited complete (001) orientation as judged from the θ-2θ X-ray diffraction pattern. Atomic force microscopic observations demonstrated that the surface of the CeO 2 layer was very smooth; the average surface roughness being as small as 1 nm. Subsequently, YBCO films were prepared by the CP process using a metal acetylacetonate-based solution on the CeO 2 -buffered MgO substrates. Both the YBCO film and CeO 2 buffer layer showed high crystallinity and fourfold symmetry in XRD θ-2θ and φ-scans, respectively. An average inductive-J c value was 0.2 MA/cm 2 at 77 K.