Abstract: Rare earth cerium complexes containing 1,10-phenanthroline and oleic acid, as well as the single ligand as control group were prepared by hydrothermal synthesis method. The composition and structure of the complexes were characterized by infrared spectroscopy, ultraviolet spectroscopy and thermogravimetric analysis. Tribological properties of lubricating oil containing different mass fractions of target products were studied by SRV-IV fretting friction and wear tester. It proved that rare earth organic complexes with Ce³⁺ as the central ion, 1,10-phenanthroline as the first ligand while oleic acid as the second ligand can significantly improve the extreme pressure and wear resistance of base oil (PAO8), and prolonged the service life of lubricating oil.