Zirconium alloys are used as fuel cladding materials in commercial reactors, which suffer from synergetic effects of irradiation and corrosion degradations. In order to evaluate the effects of irradiation on the corrosion behavior of the Zr-1Nb alloy, the alloy has been irradiated with 6.37 MeV Xe ions. The pre- and post-irradiation corrosion property modifications have been evaluated. The current paper have also reported the micro-hardness, surface roughness and phase composition modifications. After the Xe ion irradiation, unraveling surface has been observed due to the ion sputtering effect. The surface roughness and the microhardness are increased with increasing irradiation dose. The post-irradiation corrosion under LiOH solution result with lath shaped surface microstructures on the Zr-1Nb samples, which become more pronounced at higher irradiation doses. The polarization current density for the 0.5 dpa dose irradiated sample is increased by 18 times over that of the unirradiated sample, while it is about 72 times for the 2.7 dpa irradiated sample. After the ion irradiation tests, the polarization potentials are lowered (increased negatively) and the polarization resistance values are increased, compared with the unirradiated sample. The electro-chemical impedance spectra (EIS) results show that, the lower-frequency impedance values are decreased, the curvature radius of the capacitance curve is decreased and the phase angle peak is moving rightward with increasing irradiation doses. The polarization curves and the EIS results show that the ion-irradiation has increased the corrosion tendency of the Zr-1Nb alloy, and its corrosion resistance is decreased with increasing irradiation doses. The reduced corrosion resistance after the ion irradiation tests are considered to be mainly caused by the irradiation induced damages on the alloy matrix material.