Abstract: Extreme-pressure(EP) properties and anti-wear (AW) and friction-reducing properties of extraction-solvothermally prepared mono-dispersed micro-spherical MoS_2(MS-MoS_2) modified by extractant Cyanex 301 as an additive in liquid paraffin(LP) were studied and compared with those of the commercial colloidal MoS_2(CC-MoS_2) on a four-ball tester and an Optimol SRV oscillating friction and wear tester.The worn surfaces were examined with SEM and XPS,respectively.MoS_2 micro-spheres was well modified by extractant and exhibited much better performance as EP additive and AW and friction-reducing additive in LP than CC-MoS_2 did.Compared with 0.5%CC-MoS_2+LP,the friction coefficient and wear volume loss of 0.5%Cyanex 301-MoS_2+LP decreased about 15.4% and 81.7% respectively.The lubrication mechanism could be attributed to the chemical adsorption,reaction,deposition of film and the existence of the rolling friction under the boundary lubricating condition.