To simulate irradiation damage, argon ion was implanted in the Zircaloy-4 with the fluence ranging from 1×10¹⁶ to 1×10¹⁷ cm^-2, using accelerating implanter at an extraction voltage of 190 kV and liquid nitrogen temperature. Then the influence of argon ion implantation on the aqueous corrosion behavior of Zircaloy-4 was studied. The valence states of elements in the surface layer of the samples were analyzed using X-ray photoelectron spectroscopy (XPS). Transmission electron microscopy (TEM) was used to examine the microstructure of the argon-implanted samples. The potentiodynamic polarization technique was employed to evaluate the aqueous corrosion resistance of implanted Zircaloy-4 in 1 mol/L HzSO₄ solution. It is found that there appear bubbles on the surface of the samples when the argon fluence is 1×10¹⁶ cm^-2. The microstructure of argon-implanted samples changes from amorphous to partial amorphous, then to polycrystalline, and again to amorphous. The corrosion resistance of implanted samples linearly declines with the increase of fluence approximately, which is attributed to the linear increase of the irradiation damage.