Abstract: A oil-soluble dithiocarbamate molybdenum (MoDTC) was synthesized in lab and its tribological behaviors as additive in hydrogenated base oil (HVIH 6) and in self-owned additive package of API SL gasoline engine oil prior and post to oxidation were evaluated, using four-ball tester，SRV tester and PDSC method. Results indicated that MoDTC additive exhibited certain antiwear performance in HVIH 6 base stock and good extreme anti-friction performance in API SL gasoline engine oil. However, it was found that said additive was easy to be oxidized during service and thus lead to the decrease of anti-friction performance.

Key words: dithiocarbamate Molybdenum, additive, tribological performance, hydrogenated base oil