Abstract: The effects of gas carburization time on the friction and wear properties of TC11 alloy were studied. The experimental results show that after gas carburizing treatment, the carburized layer on the surface of TC11 alloy sample is mainly composed of hard layer and diffusion layer, and the structure contains TiC phase, TiO₂ and Ti₃Al phase. The hard layer is composed of equiaxed TiC grains with a grain size in the range of 8-20 μm. The structure morphology of the diffusion layer is coarse and appears in clusters, with a clear boundary between the disordered distribution and the hard layer. The thickness of the carburized layer increases with the extension of the gas carburizing holding time. After 200 h gas carburizing treatment, the thickness of the carburized layer of TC11 alloy can reach 1034 μm. At the same time, compared with the samples after carburizing and holding time of 50 h and 100 h. The microhardness increases by 21.46% and 14.67% respectively, reaching 984 HV0.2. The friction coefficient and wear rate of the gas carburized sample for 200 h decreases from 0.48 to 0.23 for the annealed state sample, and from 4.80×10^-3 mm³/(N·m) to 1.62×10^-3 mm³/(N·m). After gas carburizing treatment, the wear pattern of the sample changes from abrasive wear to adhesive and oxidative wear.