The corundum based material was prepared, with fused white corundum, commercial SiC powder and superfine Al2O3-SiC powder synthesized from clay by carbothermal reduction reaction as raw materials. The influences of SiC and Al2O3-SiC powders on the slag penetration and corrosion resistance of the material were investigated, and the slag resistance mechanisms of the additives were also discussed. It was found that the slag resistance of the corundum material by adding Al2O3-SiC and SiC powders could be improved obviously. For improving the slag resistance of the corundum material, adding Al2O3-SiC was much better than adding commercial SiC. When the Al2O3-SiC powder contacted with the molten slag, Al2O3 in the additive could be dissolved into the molten slag immediately, while SiC remained, which caused the viscosity of molten slag to be increased. So, the slag penetration and slag corrosion into the corundum material could be effectively inhibited.