Abstract: SiC was added to carbon-containing CaO-ZrO2 complex refractory to investigate its effect on the antioxidation of the refractory. The results showed that SiC can improve the antioxidation in two ways as follows: The added SiC deoxidizes CO to C so as to make up partially for the mass loss of carbon due to oxidation. Furthermore, it improves the antioxidation of the refractory by means of modifying its microstructure after heating at high temperature. The SiC additive obviously decreases the percentage of large size pores in the refractory to suppress the diffusion of ambient oxygen into the refractory. Especially the antioxidation of the refractory can be significantly improved because a dense belite (2CaO·SiO2) layer forms near the surface of the refractory as a protective coating.