Schiff base of antipyrine derivatives namely, 4-(4-methoxy-benzalideneamine) antipyrine (I), 4-(4-benzalidene-amine) antipyrine (II) and 4-(4-nitro-benzalideneamine)antipyrine (III) have been investigated as corrosion inhibitors for copper in 2 M HNO3 at different concentrations and 30±1 °C using chemical (weight loss) and electrochemical (Tafel polarization method, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM)) measurements. Generally, inhibition efficiency of the investigated compounds was found to depend on the concentration and the nature of the inhibitors. Quantum chemical calculation results show that the antipyrine ring and heteroatoms are the active sites of the three inhibitors. The adsorption behaviour of the studied inhibitors on copper surface has been studied using molecular dynamics (MD) method and density functional theory. The results indicated that the three antipyrine derivatives could adsorb on the copper surface firmly through the antipyrine ring and heteroatoms, the three inhibitors have excellent corrosion inhibition performance.