Stearyldiethanolamine and hexaammonium heptamolybdate tetrahydrate were introduced to synthesize a novel type of sulfur and phosphorus free organic molybdenum additives named HOAM.Infrared spectroscopy (IR) and inductively coupled plasma spectrum (ICP) were used to characterize the structure of synthesized additive.Thermogravimetric analysis (TGA) was used to study its thermal stability.The tribological properties and extreme pressure performances of HOAM and Molyvan 855 on market sale as additives in lithiumbase grease were evaluated using a four ball tester.The morphologies of worn surfaces were investigated by scanning electron microscopy (SEM) and the chemical nature of Mo element on the worn surface was analyzed by XANES.The results indicate that HOAM has a good thermal stability,and quite good friction reducing and extreme pressure properties.As additive in lithiumbase grease,HOAM can make the wear scar diameter of steel ball be reduced,the shape of the wear scar more regular and the furrow become shallower.During friction process,the lubrication film containing MoO2 -4 can be formed on the surface of friction pairs by chemical reaction of HOAM,it has better antiwear and friction reducing properties than Molyvan 855.