A new inhibitor derived from Chitosan and gluteraldehyde was synthesized and the efficiency of the synthesized inhibitor was screened out by electrochemical and surface scanning analysis in 0.24 M HCl. The Chitosan derivative was identified by Fourier-transformed infrared (FTIR) and the steel surface examinations were carried out via scanning electron microscope (SEM) and energy dispersive X-ray. The results of efficiency tests show very good performance as corrosion inhibitor. The corrosion rate lowered with the concentration increase of the new synthesized inhibitor. About 98.4% inhibition efficiency was measured by using 1000 ppm of the new synthesized derivative. The polarization results showed that the new synthesized derivatives have mixed inhibition effect. Langmuir isotherm was found to be the most fitted to represent the adsorption nature of the inhibitor. SEM analysis proved the presence of protective film formed by new synthesized Chitosan derivative (CH-gluteraldehyde) on the metal surface.