Abstract: In allusion to the features that hot metal bearing Ti is easy to become viscous, the impact of [Si], [Ti] content on viscosity, melting temperature, and flow properties of hot metal was studied in the lab..Relationship between the solubility of titanium in molten iron and the temperature changes was calculated and analyzed which combined with thermodynamic.The results show that molten iron become viscous which mainly affected by the dissolution and precipitation effects of titanium. [Si] has a weakening effect on the dissolution of titanium.Titanium has little effect on the viscosity of hot metal when Σ[Si+Ti] about 0.6% and [Ti] below 0.29%.The choice of appropriate blast furnace temperature is the crux of preventing that hot metal containing titanium became viscous, hot metal sticks pot, slag iron is difficult separation and so on.