Thermal oxidation (TO) treatments were conducted on Ti6Al4V under 873～1023 K for 10 h. Microstructural characteristics of the TO layers were analyzed using X-ray diffraction (XRD), glow discharge optical emission spectrometer analysis (GDOES) and optical microscope (OM). Effect of TO temperature on wear resistance of Ti6Al4V was estimated on MFT-R4000 reciprocating friction-wear testing machine. The results showed that the obtained TO layers were uniform and continuous. TO temperatures had significant impacts on the formation, surface hardness and wear resistance on TO layers. The TO layer produced at 973 K exhibited the best wear resistance indicating by higher surface hardness, lower mass loss and narrower wear trace in comparison with other TO layers.