In this work, we have synthesized three diethyl (phenylamino) methyl) phosphonate derivatives: Diethyl(phenyl(phenylamino)methyl)phosphonate(DEPAMP), Diethyl(((2-meth oxyphenyl(phenylamino)methyl)phosphonate (o-DEPAMP), Diethyl(((4-methoxy phenyl(phe nylamino)methyl)phosphonate (p-DEPAMP), whose the yields were 92%, 86% and 88% respectively. After confirmation of their structures by UV–Vis, FT-IR and NMR spectroscopic methods, the synthesized compounds were investigated as corrosion inhibitors of XC48 carbon steel in 1 mol L−1 HCl medium. The results show that the Para position is a better inhibitor in 10−3 mol L−1. Atomic Force Microscopy (AFM) was required for metallic surface characterization and the quantum chemical parameters were calculated using the Density Functional Theory (DFT) method. The adsorption energies of the inhibitors on Fe (110) surface in gas and aqueous phases were premeditated adopting the Molecular Dynamics Simulation (MDS) method. This study described the successful performance of these compounds in corrosion using weight loss measurements, Potentiodynamic Polarization and Electrochemical Impedance Spectroscopy (EIS), and discusses the correlation between experimental and theoretical, presumed DFT and MDS finding. The adsorption studies on surface were in agreement with the Langmuir adsorption isotherm model. The effects of position of OCH3 group located at ortho and para or without in chemical structure of aminophosphonates on the corrosion inhibition efficiencies of the compounds were also investigated.