A new aqueous dispersible nanocomposite as a green semi-synthetic polymer corrosion inhibitor was developed by a free radical copolymerization of o-aminophenol with anthranilic acid in presence of chitosan (CH/poly-OAP-co-AA). The developed inhibitor performance was tested by surface scanning and electrochemical analysis in aqueous HCl (0.1 M). Using (SEM) scanning electron microscope, (TEM) transmission electron microscope and (FTIR) Fourier transform infrared, the chemical composition and surface properties of CH/poly-OAP-co-AA and morphology of treated steel were explored. The outcomes of performance experiments display very impressive results as corrosion inhibitor, the effectiveness of the inhibition grew as the quantity of the newly synthesised inhibitor rose. Langmuir isotherm was detected to be the most suitable to represent chemisorption of CH/poly-OAP-co-AA on steel surface.