Abstract: To investigate the influence of tensile deformation on the nanoindentation size effect in electrodeposited nickel coating,experiments were conduct by nanoindenter and the results were predicted by two models.Both in as-deposited state and with a tensile strain of 10% nickel coating,the indentation hardness increased as the indentation dimension decreased.The experimental results can be accurately described by GCV model.However the Nix-Gao model can fit the experimental results only when the indentation depths is more than 100 nm.The indentation size effect is more pronounced in coating with tensile strain of 10% than in as-deposited state.