Mitigation of corrosion impact on environment is an important step in environmental protection. Use of environmentally friendly corrosion protection methods is very important. It is smart to choose cheap and safe to handle compounds as corrosion inhibitors. The use of green inhibitors (extracted inexpensively, from the seed endosperm of some Leguminosae plants), and investigation of their efficiency in corrosion protection is the aim of this study. As green inhibitor one kind of polysaccharides (galactomannan) from locust bean gum (also known as carob gum, carob bean gum) extracted from the seed of carob tree is used. Corrosion protection efficiency of these extracted green inhibitors was tested for carbon steel marked as: steel 39, steel 44, and iron B 500 (usually applied as reinforcing bars to concrete). Sulfuric acid solution in the presence of chloride ions was used as corrosion media. The composition of corrosion acid media used was 1 mol L<sup>-1</sup> H<sub>2</sub>SO<sub>4</sub> and 10<sup>-3</sup> mol L<sup>-1</sup> Cl<sup>-</sup> (in the form of NaCl). Electrochemical techniques such as potentiodynamic polarization methods were used for inhibitor efficiency testing
