Abstract: The friction and wear behaviors of LaF 3 nanocluster modified with compound containing nitrogen as an additive in liquid paraffin were investigated using a four ball machine. It has been found that LaF 3 nanocluster modified with compound containing nitrogen as an additive in liquid paraffin had high load carrying capacity and good antiwear and friction reduction properties. The XPS analysis of the worn surfaces indicates that a boundary lubricating film consisting of physically adsorbing film and tribochemically reaction film was generated during the friction process This contributes to improve the tribological properties of the additives in liquid paraffin.