In order to study the effect of tin ion implantation on the aqueous corrosion behavior of zirconium, specimens were implanted with tin ions to a fluence ranging from 1 X 10(20) to 5 X 10(21) ions/m(2), using a metal vapor vacuum arc source (MEVVA) at an extraction voltage of 40 kV. The valence states and depth distributions of elements in 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 tin-implanted samples. When the fluence, was greater than 1 x 10(20)ions/m(2), many small tin balls were produced in the implanted surface. The potentiodynamic polarization technique was employed to evaluate the aqueous corrosion resistance of implanted zirconium in a 1N H2SO4 solution. It was found that a significant improvement was achieved in the aqueous corrosion resistance of zirconium implanted with 1 X 10(20) ions/m(2). When the fluence is higher than 1 X 10(20) ions/m(2), the corrosion resistance of zirconium implanted with tin ions decreased compared with that of the non-implanted zirconium. Finally, the mechanism of the corrosion behavior of the tin-implanted zirconium is discussed. (C) 2004 Elsevier B.V. All rights reserved.