NaCl–KCl–TiCl_x was prepared via using titanium sponge to reduce titanium tetrachloride in a NaCl–KCl melt under a negative pressure at 1023 K. The relationship between titanium valence states and [F]/[Ti] molar ratios was investigated with successive adding potassium fluoride in the pre-prepared NaCl–KCl–TiCl_x. It was found that the average valence of titanium ions tended to be stable around 3.0 when [F]/[Ti] molar ratio was greater than 1.80. The equilibrium redox potentials, E_{Ti^{3 +} /Ti^{2 +}} , E_{Ti^{4 +} /Ti^{3 +}} , E_{Ti^{3 +} /Ti} and E_{Ti^{2 +} /Ti}, were also calculated through the obtained concentration of equilibrium titanium ions with different molar ratios of [F]/[Ti]. Meanwhile, the influence of the fluoride anion on over-potential and characteristics of titanium electrodeposition were investigated through changing the molar ratio of [F]/[Ti]. The results showed that, with the increasing of [F]/[Ti] molar ratios, the grain size of electrodeposition products became smaller, while the over-potential was higher.