Magnetic tunnel junctions (MTJs) using L 10 -ordered CoPt electrodes with perpendicular magnetic anisotropy were fabricated. Full-epitaxial CoPtMgOCoPt -MTJs were prepared onto single crystal MgO-(001) substrate by sputtering method. X-ray diffraction analyses revealed that both bottom and top CoPt electrodes were epitaxially grown with (001)-orientation. The L 10 -chemical order parameter of 0.82 was obtained for the bottom CoPt electrode deposited at substrate temperature of 600 °C. The transport measurements with applying magnetic field perpendicular to the film plane showed a tunnel magnetoresistance ratio of 6% at room temperature and 13% at 10 K.