The environmental and health hazards associated with chromium-containing solution have aroused wide public concern, so attempts have been made to find alternatives for metal finishing. In the present paper, inhibition effect of acridine on corrosion of hot dipped Zn and Zn-Al alloy coatings on steels in diluted hydrochloric acid was investigated using weight loss test, electrochemical measurement, and quantum chemistry analysis. The results showed that inhibition efficiency increased with inhibitor concentration, and the highest inhibition efficiency was up to 99%. And acridine adsorbed on coating surface by chemisorption. Quantum chemistry calculation results indicated that acridine possesses planar structure with a number of active centers, and showed a good ability of electron exchange with the coating surface.