Abstract:【Objective】In order to investigate the lubricity of methanol and isopropanol under the same load and the different rotational speed, and the effect of rotational speed on the lubricity is mainly emphasize investigated. 【Method】The tribological properties of methanol and isopropanol under 98 N, 400, 500 r/min and 600 r/min are conducted using four-ball wear machine.【Result】The experimental results show that in terms of lubrication system of methanol, the run-in stage is shortened with increasing rotational speed, and the smallest wear scar diameter is obtained at 500 r/min. In terms of the lubrication system of isopropanol, friction coefficient is kept the constant with increasing the rotational speed, but the wear scar diameter initially decreases and then increases with increasing rotational speed, and the smallest one is obtained at 500 r/min.【Conclusion】The low friction and wear of the lubrication system of methanol is attributed to the micro-bearing consisting of tungsten oxide (WO2 and WO3), methanol, friction-induced amorphous carbon and tribo-pairs. And the excellent tribological performance of the tribosystem of isopropanol is assigned to the effect of amorphous carbon with lubricity that induced by tribochemistry. Combination of optical microscope, Raman spectra, transition electron microscope, the lubri-cation mechanism of methanol and isopropanol is well investigated. The research results can provide references for the application of alcohols in the field of precision equipment.