Abstract: Molybdenum alkylsalicylate (MoAS) was prepared through the reaction of alkylsalicylic acid with molybdenum trioxide in a basic medium.Results obtained from Four-ball test demonstrated that MoAS possesses the friction-reducing and antiwear ability, particularly suitable for use as additive in those lubricating oils containing ZDDP and calcium sulphoalkylphenates. About 0.3 wt% of MoAS added into 500 SN base oil can reduce the Four-ball wear scar diam. (d_(30)~(40)) to 0.42.MoAS was found to improve the compounding property of the detergent-dispersant additives employed in engine oil.Auger Electron Spectroscopy was used in study on layers formed under Four-ball test in the presence of MoAS and molybdenum dialkyldithiocarbamate to establish the wear-prevention mechanism of the organo-molybdenum compounds.