In this study, the effect of Ascorbic acid in the corrosion behaviour of copper has been investigated in 3.5% NaCl solution (pH=9.0) using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Current-potential curve and Nyquist diagrams were obtained in different concentrations of ascorbic acid. The surface morphology of copper after their exposure to 3.5% NaCl solution with and without of ascorbic acid was examined by scanning electron microscopy (SEM). The obtained results show that; ascorbic acid inhibits corrosion of copper in 3.5% NaCl solution. Inhibition activity was determined to increase with decrease in the concentration of ascorbic acid.