The aim of this study was to assess the quality of the passive layer formed on the surface of a CoCr alloy used on dentures to see the effect on resistance riley reid schoolgirl to pitting corrosion and electrochemical parameters.Studies were performed using on potentiodynamic tests and electrochemical impedance spectroscopy.The passive layer was formed spontaneously and by electrochemical method on samples after casting and after simulation porcelain firing on metal.Samples of the passivation electrochemical characterized by the ninkasi lager improvement in corrosion resistance.Prolonging the passivation time from one to 24 hours and increasing the potential value from 0 to 200 mV improved the quality of the passive layer and all characteristics of electrochemical parameters.