A deoxyribonucleic acid(DNA)corrosion inhibitor was prepared by dissolving a mixture of primers with a length of 20~80 bases in a nucleic acid buffer. Linear polarization and electrochemical impedance spectroscopy(EIS)were employed to investigate the effect of coexisting anions, HCO^-₃ and SO^2-₄, on the chloride-induced corrosion of reinforced steel in simulated concrete pore solution for the corrosion inhibition of DNA. After different treatments, X-ray photoelectron spectroscopy(XPS)was used to characterize the structure of the surface membrane of the reinforced steel. The results show that the DNA corrosion inhibitor has a good anticorrosive effect on the steel reinforcement. However, the presence of coexisting anion HCO^-₃ accelerates the corrosion rate of the reinforced steel. The addition of the DNA corrosion inhibitor alleviates the steel corrosion process and its rust inhibition efficiency is comparable to that of the commonly used commercial corrosion inhibitor(the main component is sodium phosphate). The presence of SO^2-₄ increases the corrosion rate of the reinforced steel, and its corrosion inhibiting efficiency is even higher than that of the commercial one under the same conditions.