Abstract: In present work, we synthesized three novel benzotriazole based ionic liquids firstly. The corrosion inhibiting properties were researched by electrochemical measurements using benzotriazole as corrosion inhibitors in 0.5 M H₂SO₄ aqueous solution. The results concluded from electrochemical impedance spectroscopy and potentiodynamic polarization curves indicated that three ionic liquids effectively inhibited the corrosion of bronze. Then three ionic liquids were utilized as additives in PEG base oil to probe the friction reducing and antiwear properties. Results indicate that three ionic liquids reduced the friction coefficient and wear volume of PEG base oil significantly, which further demonstrate excellent tribological performances of three ionic liquids. The worn surfaces were analyzed by scanning electron microscope and X-ray photoelectron spectrometer to probe the lubrication mechanisms. It was found that boundary lubricating film consisted of ionic liquids adsorption layer and tribochemical products was responsible for the excellent tribological properties. In summary, novel benzotriazole based ionic liquids were versatile materials with two outstanding abilities, i.e. corrosion inhibiting and lubricating properties, which were of considerable significance for application of ILs in industry.