Abstract: In order to study the effects of sliding plate grinding powder on the properties of magnesia-alumina castable，95% magnesia，88% alumina and silica fume were used as main raw materials to prepare magnesia-alumina castable. The effects of 2%，4% and 6% of sliding plate grinding powder on bulk density，apparent porosity，modulus of rupture at room temperature， slag penetration resistance and slag erosion resistance of magnesia-alumina castable were studied. According to the comprehensive analysis，when the addition amount of sliding plate grinding powder is 2%，the application effect is the best.

Key words: Magnesia-alumina castable, Sliding plate grinding powder, Physical properties at room temperature, Slag penetration resistance