The experiment of oxidation resistance mechanism for silicon carbide in arc heater is introduced. Test
conditions were confirmed according to active and passive oxidation mechanism of the SiC composite material. The results indicated that the silicon dioxide (SiO2) film appeared on the surface of silicon carbide when the surface temperature is less than the transition temperature;the film prevented the ablation of the materials because that decreased the reaction between oxygen and carbon materials. On the other hand,the silicon carbide surface ablated when the surface temperature is higher than the transition temperature.