Abstract: The desulphurization and reduction process of synthetic titaniferous slag with molten pig iron have been studied simulating the temperature variation from the dropping zone to hearth of the blast furnace. The variation of [V],[Ti],[Si] and [S] contents during reaction and the relation between the slag composition and the desulphurization capacity, TiO₂ reduction have been examined. A slag composition is recommended in order to decrease TiO₂ reduction and preserve the desulphurizing capacity when smelting titanomagnetite with TiO₂ content about 25% in the slag.