A (polyvinylpyrrolidone (PVP)/deoxyribonucleic acid (DNA))(n) coating was fabricated via layer-by-layer (LbL) assembly dip coating method. The surface morphologies, chemical compositions and corrosion resistances of the coatings were investigated using field-emission scanning electron microscopy, X-ray photoelectron spectrometer, Fourier transform infrared, X-ray diffractometer and electrochemical and hydrogen evolution measurements. The results indicated that the (PVP/DNA)(n) coating shows a smooth surface with shallow scratches and some corrosion cracks, which possesses a good corrosion resistance in simulated body fluid, especially for n = 20. The (PVP/DNA)(n) coating can be used as a inducer to construct a biomimetic biocompatible Ca-P coating on Mg alloys. Additionally, we suggest and discuss a corrosion mechanism for the coating.