Abstract: Adopting A85 homogenized bauxite，96 sintered magnesia，corundum powder， alumina magnesium spinel powder，silicon powder，alumina powder，carbon and silicon-based additives as raw materials，the effects of carbon materials and silicon-based additives on the properties of castables were studied through experiments. The silicon-based additives can enhance and inhibit the oxidation of carbon materials，with the introduction amounts of 0，0.5%，1%，1.5% and 2% respectively. The results show that with the introduction of silicon-based additives，the porosity first decreases and then increases，the bulk density first increases and then decreases， the black core area gradually increases，and the high temperature performance first improves and then decreases. Comprehensive analysis shows that when the amount of silicon-based additives is 1%，the performance of castable is the best

Key words: Aluminum magnesium castable, Silicon-based additives, Oxidation resistance, HMOR