In this study , the inhibtion effect of amino nictino nitril on carbon steel corrosion in 0.5 M Hcl solution was studied . 
for this aim , electrochemical techniques such as potentiodynamic polarization curves,weight loss(WL) were used . it was 
showen that , the amino nictino nitril has aremarkable inhibtion efficiency on the corrosion of carbon steel in 0.5 M Hcl 
solution . polarization measurements indicated that,the studied inhibitor acts as mixed type corrosion inhibitor with 
predominatly control of cathodic reaction. The inhibition efficiency debends on Athe concentration of inhibitor and 
reaches 92 % at .001 M Amino nictino nitril was discussed in terms of blocking of electrode surface by adsorption of 
inhibitor molecules through active centers . the adsorption of amino nictino nitril molecules on the carbon steel surface 
obeys Langmuir adsorption isotherm.