Abstract: The viscosity of molten iron containing titanium was measured with a oscillating cup viscometer at elevated temperatures. The effects of titanium and silicon on the viscosity, viscous activation energy, solidification temperature, and solidification rate of molten iron were studied during the cooling process. It is found that there is little difference in viscosity among molten irons containing different contents of titanium above the solidification temperature, and their viscous activation energies change in the range of 37.07 kJ·mol^-1 to 44.03 kJ·mol^-1. There is great influence upon the solidification temperature and solidification rate by adding titanium into molten iron, and the higher the titanium content, the higher the solidification temperature and solidification rate. Low silicon content is the main reason for low solidification temperature of molten iron containing V and Ti.