In order to study the synergistic performance of extremepressure and antiwear of fullerene and nanotungsten disulfide,the tribological behaviors of the compound of fullerene and nanotungsten disulfide were investigated by a fourball test machine.The wearspot appearance of the test steel ball was analyzed by scanning electron microscopy,and the synergistic mechanism of fullerenes and nanotungsten disulfide was analyzed.Results show that the fullerene and nanotungsten disulfide have no obvious effect on the friction reduction and antiwear of PAO base oil,but the compound of fullerene and nanotungsten disulfide can obviously improve the friction reduction and antiwear performance of PAO base oil,and the synergistic effect of 0.01% fullerene and 0.005% tungsten disulfide is the best.However,the extremepressure performance of the base oil are not improved by the compound of fullerene and nanotungsten disulfide.There is no chemical reaction between fullerene and nanosized tungsten disulfide to form new materials in the friction process,which indicates that the reason that fullerenes and nanotungsten disulfide can reduce the friction coefficient and wear spot diameter is that they form a physical synergistic relationship in the PAO base oil.