The hindrance effect of pharmaceutical drug (Azathi oprine) on metal corrosion in 2M hydrochloric acid was done by electrochemical (Tafel polarization curves, EFME IS), and chemical (WL) methods. Polarization plots for compounds how that physical behavior for inhibitor. The temperature effect on inhibition corrosion hav e explained, the activation parameter was measured. Impedance El ectrochemical work showed that the existence of thi s drug decreases the capacitance double layer(C dl ),and increment the resistance of charge transfer ( R ct ). The drug absorption on metal surface was obeyed Temkin’s iso therm. The morphology of surface on metal examples were evaluated using (EDX and SEM) analysis. The mechan ism of inhibition process was explained for Azathioprine on the metal surface.