A Corrosion inhibition effect of a new compound on mild steel in 6 mol/L HCl medium was investigated by electrochemical impedance spectroscopy, Tafel polarization and mass loss methods. The results of mass loss and electrochemical methods indicated inhibition efficiency increase with increasing in inhibitor concentration. Polarization investigation revealed that inhibitor is mixed type inhibitor. The results of Nyquist plots were analyzed through appropriate equivalent circuit model. The thermodynamic parameters showed chemisorption-physisorption of inhibitor on mild steel surface in acid media.