Impact of acidic solution with potassium rhodanide on partial electrode reactions was studied in AMAG-200 metallic glass (MG). Increase of acidity leads to growth of electrochemical reactions. With (mol/l) growth of potassium rhodanide in hydrochloric solution, radius of a circular Nyquist diagram increases that testifies to better corrosion resistance of AMAG-200 MG in mentioned environment. Surface coverage ratio of rhodanide-ions increases up to the 0.9—0.99 maximum with adding of potassium rhodanide. Because of the physic-mechanical features of the solution, surface co-adsorption of rhodanide-ions, Сl-, H3O+ ions, and НSCN, Н2О molecules is possible that can lead to competitive adsorption, noticing in diagrams.