In order to study the effect of chromium ion implantation on the aqueous corrosion behavior of zirconium, specimens were implanted by chromium ions with a dose range from 1 X 10(16) to 1 X 10(17) ions/cm(2), using MEVVA source at an extracted voltage of 40 kV. The valence and elements penetration distribution of the surface layer were analyzed by X-ray photoelectron spectroscopy (XPS) and auger electron spectroscopy (AES), respectively. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine the micro-morphology and microstructure of chromium-implanted samples. The potentiodynamic polarization measurement was employed to value the aqueous corrosion resistance of zirconium in a 1N H2SO4 solution. It was found that a significant improvement was achieved in the aqueous corrosion resistance of zirconium compared with that of as-received zirconium. The mechanism of the corrosion resistance improvement of chromium-implanted zirconium is probably due to the addition of the chromium oxide dispersoid into the zirconium matrix. (C) 2004 Elsevier B.V. All rights reserved.