Abstract:A novel organic sulphur ester containing nbutyl dithiocarbamate structure (CNSB) was synthesized from the etherification reaction in the presence of catalyst. The tribological properties of CNSB as lubricant additive in 100 N base stock were evaluated using a fourball machine, the surface topography and element composition of the abraded steel were analyzed through scanning electron microscope (SEM) and energy dispersive spectrometer (EDS) respectively.The results show that,CNSB,as a lubricating oil additive has good extreme pressure antiwear performance,and is superior to dialkyl disulfide generation of zinc phosphate(noted as ZDDP) at the same conditions. SEM and EDS analysis shows that CNSB will decompose and produce a chemical reaction on the surface of the friction pair during the friction process, so a dense protective film consisting of organic sulfur and boron oxides is formed, which can effectively reduce the abrasion and wear on the steel ball surface.The B element in CNSB has a synergistic effect with S element,which also plays a certain antiwear and friction reducing effect.