HIP (hot isostatic pressed) high-purity alumina was modified by Ti-ion implantation in a MEVVA (Metal Vapor Vacuum Arc) implanter. The samples were implanted by Ti ions with nominal doses 5×1016 to 1×1018 ions/cm2 under ambient temperature. The effects of titanium implantation and the ion dose implanted on the microstructures and mechanical properties of the ceramics were studied. After implanted by Ti ions, the maximum nanohardness of the as-implanted ceramics were increased about 20%; the bending strength were increased about 22%; the life of the alumina cutting tools were about 2 times longer than before. The result showed that all the factors of the improvement of the ceramic surface states played an important role on the mechanical properties after implantation.