A mixed solution that had a length of 20 to 80 bases of each primer in nucleic acid buffer was used as nucleic acid corrosion inhibitor. The corrosion inhibition effect and mechanism of nucleic acid corrosion inhibitor on rebar in simulated concrete pore(SCP) solutions with different concentrations of NaCl were investigated by electrochemical impedance spectroscopy and potentiodynamic polarization.The best dosage of the nucleic acid corrosion inhibitor was also investigated. The chemical composition of the adsorption films on the rebar surface was investigated using X ray photoelectron spectroscopy(XPS). It is found that the nucleic acid has an excellent corrosion inhibition effect, and the added amount of 4% nucleic acid by simulated concrete pore solutions mass is the best dosage. There is an excellent synergistic effect between nucleic acid and rebar. The nucleic acid is greatly adhered to the rebar surface and a dense film is formed which can restrict the corrosion attack and provide superior corrosion inhibition.