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In this investigation, NiTi alloys with different Ni contents were fabricated by mechanical alloy and spark plasma sintering (SPS) at 1000℃. Microhardness, mechanical and tribological properties of the NiTi alloys with different Ni contents were evaluated by the microhardness tester, universal testing machine and friction and wear tester. The wear volumes and wear rates were calculated by three-dimensional white light profilometer. The wear morphologies of NiTi alloys were analyzed by scanning electron microscopy (SEM) with energy disperse spectroscopy (EDS). The experimental results showed that the microstructures of NiTi alloy were uniformed in general. When the content of Ni was lower than 50 wt. %, the NiTi phase and NiTi₂ phase were presented in the microstructures. While the NiTi phase and Ni₃Ti phase were presented in the microstructures with more than 50 wt. % Ni contents. When the nickel content is 50 wt. %, the microhardness of the alloys were significantly improved. For the compressive strengths, these of NiTi were decreased as the Ni contents increased. When the nickel content is 55 wt. %, the tribological properties of the alloy can be significantly improved, because the E/H value of the NiTi alloy is the lowest. The wear mechanisms of NiTi alloy are abrasive wear and fatigue wear through the wear surfaces examined by SEM and EDS.