The liquid lithium blanket for fusion reactors requires an electrically insulating coating on the duct to minimize the magnetohydrodynamic pressure drop that occurs during the flow of liquid metal in a magnetic field. Calcium oxide (CaO) is a good candidate for the coating material because it is an excellent electrical insulator and it is stable in a liquid lithium environment. In this paper, details are presented on metalorganic chemical-vapor deposition method that was used to fabricate the CaO coating. Composition and phase analyses of the coating were performed by energy dispersive X-ray analysis and X-ray diffraction. Scanning electron microscopy images show that the coating did not crack after several thermal cycles from room temperature to 715°C. The resistance of the coating is high enough for an insulating coating on the liquid lithium blanket of fusion reactors.