In view of the huge advantages of green corrosion inhibitors and in order to solve the problem of environmental pollution in the process of cleaning the zinc metal, this study is the evaluation of Bagassa guianensis extract on the corrosion behaviour of zinc in chloride medium (3%) was realised using electrochemical techniques (polarisation and AC impedance). This study demonstrated that the plant extract of Bagassa guianensis is a real as sustainable and green inhibitor for zinc corrosion in 3% NaCl with an inhibition efficiency of about 97% at 100 ppm. The electrochemical reactions were both impacted by the existence of the green inhibitor on the basis of the polarization curves and a change towards the positive potentials was measured in the presence of the extract in 3% NaCl. A CPEα, Q determined by fit and graphical methods plotted by synthetic data, was utilized. In order to determine the chemical compounds mainly responsible for the corrosion inhibition of the extract, electrochemical studies were carried out on each family contained in the plant extract. To comprehend the adsorption mechanism of total extract and flavonoids extract for zinc in the saline solution, XPS technique was accomplished. The obtained results indicated the establishment of protective film inclosing the Bagassa guianensis extract and the flavonoids compounds. The mechanism of corrosion protection of Bagassa guianensis extract was discussed with PDP, EIS, isothermal adsorption model and XPS technique.