Three kinds of water soluble imidazoline derivatives were synthesized with 6Aminocaproic acid and DETA,TETA,TEPA,and their tribological performance as waterbased lubricants of YG8 cemented carbide was investigated on the MMW1B Type of friction and wear tester.Surface wear morphology,3D morphology,elemental distribution and the chemical composition of the YG8 ball surface were analyzed by using Scanning Electron Microscopy(SEM),vk9700,EDS and XPS separately.Results indicate that three kinds of additives have good water solubility and excellent extreme pressure and antiwear performances.The additive with TEPA chain has the best wear resistance,and the additive with TETA chain has the best friction reducing performance.The organic N compisite films are formed on the YG8 ball surface because of the physical and chemical adsorption of the three additives during the process of friction,which can prevent the wear and oxidation of the steel ball.High nitrogen containing imidazoline has the best tribological properties.