The sulphide capacities of CaO-SiO 2 -Al 2 O 3 -MgO-TiO 2 -Fe t O slags with high titanium and Fe t O were measured by gas-slag equilibration technique to reveal the effect of slag composition and temperature on the sulphide capacities of slags. The results showed that sulphide capacities enhanced with the increase of temperature, basicity, Fe t O, and MgO contents, TiO 2 content increased first and then decreased in the range of 10 wt-% to 20 wt-%; the influence became negligible as the TiO 2 content exceeded 25 wt-%. MgO significantly increased the sulphide capacities of slag in the range of 6 wt-% to 8 wt-%, continued to increase the MgO content, and the increasing trend of Log C S became slowly; Fe t O content increased from 3 wt-% to 9 wt-%, sulphide capacities increased slowly, increased dramatically in the range of 9 wt-% to 15 wt-%. Meanwhile, comparing the optical basicity models found Zhang and Tsao's models are close to the experimentally determined values.