In our study, the green method was adopted using green tea leaf extract in the preparation of nano-magnesium oxide. This method was chosen in the preparation because it reduces toxicity and produces low-cost materials that do not require high energy and are environmentally friendly. The prepared magnesium oxide was diagnosed using UV-Vis, FTIR, XRD and FESEM techniques. After diagnosis, the prepared MgO NPs was used in the adsorption of heavy metal ions, lead and Cadmium, to determine the optimum conditions for the oxide adsorption process and study the experimental data through adsorption isotherms. (Langmuir, Freundlich and Temkin) in order to clarify how the correlation occurs between the adsorbate ions and the surface of the adsorbent material to understand the mechanism of adsorption.