Abstract: In order to study the tribological behavior of MoS₂-Ti thin films sliding against 9Cr18 steel, W-DLC and DLC thin films, MoS₂-Ti, W-DLC and DLC films are deposited on 9Cr18 steel by magnetron sputtering and plasma enhanced chemical vapor deposition technology respetively. The morphology, composition and phase structure of the films are characterized by SEM, EDS and XRD. The hardness and tribological properties of MoS₂-Ti films sliding against 9Cr18 steel, W-DLC and DLC are investigated by hardness tester and ball-on-disc tribometer respectively. The results show that the MoS₂-Ti films sliding against DLC have the lowest friction coefficient and wear rate among these three mating materials. Compared to the MoS₂-Ti films sliding against the 9Cr18 ball, MoS₂-Ti films and W-DLC film does not reduce the friction coefficient and wear rate. The wear mechanism of MoS₂-Ti films and W-DLC is adhesive wear and abrasive wear, while the wear mechanism of MoS₂-Ti films and DLC is adhesive wear.