Abstract:Effect of Al2O3 powder addition on properties of Basic castable refractories is investigated with magnesite as main raw materials. We investigated properties of the castable with the different Al2O3 powder addition by drying at 110℃ for 24 hours and sintering at 1500℃ for 3 hours. The experiment shows that. more or less 5% Al2O3 powder not only increase the ratio of apparent porosity but also decrease its cold crushing strength and slag resistance to some degree. The Basic castable refractories has good properties when ddition of Al2O3 powder is 5%,It can remarkably improve properties.