Corrosion of aluminium anode in the seawater will reduce the life of the aluminum-air cell. It has been recognized that addition of inhibitor into the seawater electrolyte is an effective method that may prevent the corrosion of aluminium anode.The corrosion inhibition behavior of aluminium anode after addition of CeCl3 with different concentrations in simulated seawater has been investigated in this paper. EIS results showed that there was a significant increase of corrosion resistance when the concentration of CeCl3 reached 500mg·L-1 in simulated seawater, compared to the case without inhibitor. Potentiodynamic polarization curves showed that CeCl3 was a cathodic inhibitor in simulated seawater. SEM and XPS confirmed that the cerium oxide/hydroxide were formed at micro-cathodic areas of aluminum surface,which decreased the corrosion rate of aluminium anode.