The work aims to study the influences of different environment (vacuum, PAO, different counterparts and tem-perature) on tribological properties of MoS2/C composite films, and explore the friction mechanism. MoS2/C composite films were deposited by direct current magnetron sputtering (DCMS) and high power impulse magnetron sputtering (HiPIMS) on high-speed steel and silicon substrate. Tribological behavior of the composite films in air, PAO, and different temperature were tested with a multifunction tribometer, and tribological properties of the composite films in the vacuum and different counterparts were evaluated with a vacuum tribometer. The morphologies and chemical composition of films and wear debris were analyzed by field emission scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and confocal laser Raman spectroscopy. In vacuum, all films were worn out, except ZrO2 counterparts. Films with MoS2 content more than 50% could maintain low friction coefficient in the vacuum, about 0.1. In PAO, the friction coefficient was 0.08 in the boundary lubrication stage, and was 0.1 in hydrodynamic lubrication. The friction coefficient decreased from 0.09 to 0.026 with the temperature increasing from 25 ℃ to 300 ℃, but the film failed at 450 s at 700 ℃. In vacuum, ZrO2 and Al2O3 can reduce the adhesion of MoS2/C composite film as counterparts and the composite films with MoS2 content more than 50% exhibit better tribological properties. In PAO lubricating oil, the tribological property mainly depends on the properties of PAO. In high-temperature, severe graphitization and recrystallization of MoS2 in the films can reduce the coefficient of friction of the film.