The effect of the Cu addition on the passivation behavior of hyper duplex stainless steels in both the active and passive states was investigated using the electrochemical tests, a scanning electron microscope-energy dispersive spectroscope, a scanning Auger multi-probe analysis and an X-ray photoelectron spectroscopy analysis in sulfuric acid solution. In the active region of −0.2 V_SCE, the Cu addition to the base alloy has a positive effect on the general corrosion resistance due to the novel Cu enriched on the surface. In the passive region of 0.6 V_SCE, the Cu addition to the base alloy degraded the stability of passive film due to an increase of the formation of Cr enriched inclusion such as (Cr, Mn, Al) oxides and (Cr, Mn, Al, Fe) oxides acting as the defect in the passive film, resulting in deteriorating general corrosion resistance.