The effects of mullite coating by sol-gel method and the particle sizes of SiC on the oxidation behavior of the recrystallized SiC were studied. The results showed that the oxidation resistance could be increased by the mullite coating formed on the surface of recrystallized silicon carbide at high temperature and with the increase of the thickness of mullite coating, having well effects both by mullite coating and coarse particles of the recrystallized SiC.