Abstract: The preparation of Ti-Al based alloy by aluminothermic reduction of Ti-bearing slag is a promising process due to the low cost of raw materials and products.To obtain a good slag-metal separation and required composition of Ti Al alloy,the material proportioning calculations are necessary. In this work,the general equations of material proportioning calculations for aluminothermic reduction of Ti oxides were derived.Using the obtained equations,the material proportioning calculations for aluminothermic reduction of acid-soluble titanium slag were conducted,and the slag composition,alloy composition and distribution of elements between alloy and slag phases were also calculated. The general equations derived in present study can be used in design of aluminothermic reduction process of metallic oxides system.