Tribological behavior of HEtHex(TFS) as additive in liquid paraffin(LP, simulant of lubricating base oils) with different mass fractions for the contact of steel/steel ball was investigated. At the same time, the effects of the temperature and load on the anti-friction and anti-wear properties were studied. The morpho-logies and the elemental compositions of the worn surfaces were analyzed using scanning electron microscope(SEM) and X-ray energy spectroscopy(EDS). The results showed that the value of extreme-pressure increased significantly, and the antifriction and anti-wear properties of the LP improved with the addition of HEtHex-(TFS). The optimum value of HEtHex(TFS) as additive in the LP was 0.75%(mass fraction). The best abilities for the anti-friction and anti-wear property of 0.75% HEtHex(TFS) in the LP were found at 25 ℃, 294 and 196 N, respectively. The results of the elemental analysis showed that a protective boundary film was formed on the steel ball surface and it caused that the anti-friction and anti-wear properties was improved.