This paper provides a mechanism to study aluminum diffusion microstructure, phase structure and different properties of the aluminized layer in carbon steel. The results of aluminized treatment in saturated medium lead to the formation of diffusion layer coating that contains iron aluminide and a- solid solution of aluminum in the unit cell of iron. The effect of aluminizing process parameters on the aluminizing layer, especially the effect of temperature and time, has been shown to increase the depth of the aluminized layer when temperature and time increase, but the effect of temperature is greater than time.