Pure Ni with a high density of nanoscale twins (NT Ni) had been synthesized by electrodeposition technique. Its corrosion property was investigated in 0.1 mol/L H3BO3 + 0.025 mol/L Na2B4O7 buffer solution with pH 8.4 by electrochemical techniques and compared with its cast counterpart. The results demonstrated that NT structure has little effect on the point defect concentration in the passive film. However, the NT structure can greatly influence the film thickness and the diffusion coefficient (D-d) of point defect, which are responsible for the formation of a thinner, perfect passive film and finally gives rise to a higher corrosion resistance for NT Ni. This indicates that the material may have great potential as a substitute of the nuclear steam generator tube material. Crown Copyright (C) 2008 Published by Elsevier Ltd. All rights reserved.