A conducting oxidation-resistant carbide alloy layer can be formed on the surface of graphite electrode by means of the surface alloying method in a molden mixture. This compact layer can effectively reduce the consumption of graphite electrode due to carbon oxidation during arc furnace steelmaking. The process of alloy layer growth is found to be controlled by the non-steady state solid phase diffusion of carbon atom. A kinetic model was established thereupon. The model prediction is in good agreement with experimental data.