Ti6Al4V alloy samples were modified by implanting silver ion at the dose of 5×1016, 1×1017, 5×1017 and 9×1017 ions/cm2 under an acceleration voltage of 30 kV. The potentiodynamic polarization curve was used to investigate the corrosion resistance of un-implanted and Ag+-ion-implanted Ti6Al4V alloy in Hank’s solution. The glancing angle X-ray diffraction and X-ray photoelectron spectroscopy were used to investigate the phase composition and chemical states of elements on Ti6Al4V alloy surface. The results show that silver ion implantation can improve the corrosion resistance of Ti6Al4V alloy in Hank’s solution. The corrosion current density of Ag+-ion-implanted Ti6Al4V alloy changed slightly with the Ag ion dose increasing. The corrosion resistance improvement of Ag+-ion-implanted Ti6Al4V alloy samples in Hank’s solution is attributed to all kinds of corrosion-resistant oxide layer, surface alloy layer produced during ion implantation and Ag and TiAg existing in the outermost surface of the Ag+-ion-implanted Ti6Al4V alloy