Abstract: The acidolysis performance of acid-soluble titanium slag is studied via phase and content analyzing in this paper.The experiment results show that the acidolysis rate of titanium slag was affected by the mass content of TiO₂ and Rutile and phase in titanium slag.The acidolysis performance of anosovite impact directly on the acidolysis rate of titanium slag, particularly the Fe content in anosovite.Additionally, the mass content of TiO₂ and rutile in titanium slag would affect the performance of titanium slag too.The FeO and MgO in titanium slag is beneficial to the enhancement of titanium slag while the CaO、SiO₂ and Al₂O₃ go against.Keeping TFe (equivalent) /TTi ratio upper 0.28 in titanium slag would make the acidolysis rate come up to 95% or higher.