Chromium nitride (CrN) coatings deposited by physical vapor deposition (PVD) processes have been adopted for wear protection of cutting tools and various metallic components for years. To further improve the electrochemical performances of CrN coatings, duplex CrNx coatings of various stoichimetries and gradient coating were prepared by cathodic arc evaporation. The chemical analysis was carried out by X-ray photoelectron spectroscopy (XPS). The crystallographic structure was investigated by X-ray diffraction (XRD). The composition, structure of the coatings varied as a function of nitrogen pressure. The potentiodynamic polarization was examined by Zahner IM6e electrochemical workstation, and the corrosive surface was detected by scanning electron microscopy (SEM). The results showed that the graded coating had an better electrochemical performance than duplex CrN coating. The relationship of microstructure and properties was studied, and a model of gradient CrN coating was constituted.