A process of producing a cathode electrocatalyst for metal-air batteries includes providing a carbon source suspension, a metal source solution, and a nitrogen source solution, subjecting the carbon source suspension and the metal source solution to a low-temperature hydrothermal reaction, subjecting a first precursor-containing product thus formed and the nitrogen source solution to a high-temperature hydrothermal reaction, and subjecting a second precursor thus formed to a heating treatment under a protective atmosphere. A cathode electrocatalyst produced by the process is also disclosed.