The electrochemical behavior of commercially pure Ti (CP Ti) in certain ionic liquids (ILs), such as choline chloride-urea (ChCl-urea), ChCl-ZnCl2, 1-ethyl-3-methylimidazolium chloride aluminum chloride (EMIC-AlCl3) and N-butyl-N-methylpyrrolidinium dicyanamide (BMP-DCA) were investigated by conducting open circuit potential (OCP) measurement, potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS) in glove box. The potentiodynamic polarization measurement results show that CP Ti could be passivated in BMP-DCA, ChCl-urea and ChCl-ZnCl2 ILs. However, in EMIC-AlCl3 ionic liquid, the polarization curve only exhibited active dissolution behavior, without the presence of a passive region. The passivation behavior of CP Ti in ILs was also characterized by means of X-ray photoelectron spectroscopy (XPS) to examine the roles of ILs with different chemical structures. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.035207jes] All rights reserved.