Abstract: Two sulfur-containing organic borates were prepared and the antiwear property ofthese borates added into white oil and n-tetradecane,and theeffect of dodecyl amine on antiwearproperty of the synthesized borates were measured using a four-ball tester and a ring-block tester. The results were compared with that of the propane 1,2-diol dodecyl sulfide,sulfurized cotton seedoil and tridodecyl borate,X-ray photoelectron spectroscopy(XPS)was used to examine the rubbedsurfaces of the test blocks. It was found that on four-ball tests,S-containing organic borates possess higher load-carryingcapacity than tridodecyl borate,and with the addition of dOdecyl amine,the load-carrying capacitycan be increased remarkably. As on ring-block tests,the S-containing organic borates exhibits apoorer antiwear property than tridodecyl borate,but with the addition of dodecyl amine,theantiwear property of the S-containing borates can be increased.XPS analyses indicate that sulfur onthe rubbed surfaces exists in the forms of organic sulfide and FeSO4,and the addition of aminereduces the adsorption and reaction of sulfur to the rubbing surfaces.