The Ti6Al4V alloy has a series of advantages such as low density, corrosion resistance and high strength. Along with these advantages, the low wear resistance of the Ti6Al4V alloy prevents its wide application in the industry. Ti6Al4V alloy is also frequently used in the aerospace industry. Thus, the wear resistance under vacuum condition is as important as the wear resistance under ambient air. In this study, it is investigated that the wear resistance of the Ti6Al4V alloy improved by glow discharge plasma oxidation at 3 different temperatures. The characterization of the formed oxide layers is determined by the Vickers micro-hardness tester, scanning electric microscope, 3D profilometer, energy distributor X-ray spectrometer, atomic force microscope and X-ray diffractometer. The wear resistance of the untreated and plasma oxidized samples are tested under 1 and 2 N constant normal load under ambient air and vacuum conditions. It has been determined that in the both wear conditions, oxidized samples have lower wear rates than untreated samples. The best wear resistance in both wear conditions is obtained in the sample with the highest hardness value. In addition, it has been determined that the wear resistance under vacuum condition is higher than the ambient air.