Abstract: Study on reduction of vanadium oxide in titania slag containing 0~5% MnO. The results of experiment show that the apparent equilibrium constant (IgK_si-v) of Si-V increases with increasing initial MnO,and decrease with increasing initial TiO₂,with increasing slag basicity when R >1. 2. The reduction reaction of vanadium oxide can't reach equilibrium in the blast furnace. The reduction of vanadium oxide is restricted by dynamic condition. Reduction reaction is one of two steps. The apparent activation energy is equal to 172 kJ/mol. The reduction rate of vanadium oxide is restricted by V³⁺ diffusion in slag during initial reduction. But it is restricted by SiO₂ reductionrate when Si-V coupled reaction has reached equibrium. Some measures of increasing the reduction rate of vanadium oxide were pointed out.