The Corrosion inhibition of copper in nitric acid has been studied by 8-hydroxy-7-(-4-methoxy-phenylazo) quinoline-5-sulfonic acid using weight loss and electrochemical measurements. It was found that the (HQSA) act as a good corrosion inhibitor for copper in all concentrations of the inhibitor. The inhibition action depends on the concentration of the (HQSA) in the acid solution. Results for weight loss and electrochemical measurements indicate that inhibition efficiency increases with increasing inhibitor concentration. Polarization curves revealed that this compound is mixed type inhibitor. The adsorption of (HQSA) on the surface of the copper specimens obeys Temkin adsorption isotherm. Some thermodynamic and kinetic parameters for the corrosion process were estimated, and the values support the results obtained. Some quantum chemical parameters for (HQSA) were calculated.