Direct fabrication of light emitting devices on metal substrates is highly desirable due to their advantages of high thermal conductivity and light reflection. In this work, we demonstrated a feasibility of directly fabricating ZnO-based ultraviolet laser diodes on metal substrates. By introducing an anti-oxidation buffer layer, Au/MgO/ZnO metal-insulator-semiconductor heterojunction devices are successfully fabricated on the copper substrate. Electrically pumped ultraviolet random lasing was achieved from ZnO active layer. The use of copper substrate offers some merits, including lower thermal effect and higher stability of emission wavelength.