Abstract: The effect of TiO₂ and TiC content on the melting properties of medium-titanium slag at different conditions was investigated using melting properties instrument (RTW). And the viscosity of slag in the tuyere areas of blast furnace (BF) was measured. The results show that,under a reducing atmosphere,the viscosity of the medium-titaniun slag has an obvious turning point with changing temperature. The melting temperature of the slag increases with increasing TiO₂ content of the slag. However,under a neutral atmosphere,both the viscosity and melting temperature of the slag decrease with increase in the content of TiO₂.The viscosity and melting temperature of the slag also increase sharply as the content of TiC increases. The slag in the tuyere areas has poor stability because of the high Ti C and Ti N content of slag. The results can be used as reference for choosing proper operation system of medium-titamium slag in blast furnace.