The effect of ion implantation of yttrium on the oxidation behavior of Ni3Al base alloy IC6 at 1100°C was investigated by SEM/EDS, TEM and XRD methods. The results indicated that after Y ion implantation, the surface of IC6 alloy changed from large column crystals to fine distributed nano-crystals, and the density of dislocations in distorted region increased with the implanted ions dose, which can act as high-diffusivity path and oxide core. Comparing to un-implanted IC6 alloy, Y-implantation increased the oxidation rate of IC6 alloy in initial 25 h at 1100°C, but decreased the maximum weight gain and the oxidation rate in final period. Moreover, the oxide scales of Y-implanted IC6 alloy were more continuous and compact due to the benefit effect of yttrium, and had better coherence to substrate through reduction of oxide grain size resulting in oxide scale plasticity improvement. Hence the proper amount of implanted Y could improve the oxidation resistance of IC6 alloy at 1100°C in air slightly.