The corrosion inhibition of steel S300 in 1M HCl by Extracts of Cuminum cyminum was investigated by using weight loss measurements, Potentiodynamic Polarization Curves and Electrochemical Impedance Spectroscopy (EIS). The polarization Curves reveal that extracts of C. cyminum is a mixed-type inhibitor. The results show that the inhibition efficiency increases with the increasing of extract concentration to reach 97.49 % at 1. 3 g/l and decreases with temperature. Cumin extract is adsorbed on the steel surface according Langmuir isotherm. The adsorption parameters, enthalpy and activation energy were determined. The effect of temperature was studied and discussed. Keywords: Cumin, steel, Corrosion, inhibition
