The Removal of Acid Green by adsorption on Activated carbon-MnO -Nanocomposite, under optimized conditions has been studied. The adsorption data were analyzed by using adsorption isotherms like Langmuir, Freundlich, Tempkin, Dubinin-Radushkevich and Halsey isotherms were also studied. The study has found that the Nanocomposite adsorbent play an effective role in removing the Acid Green from its aqueous solution.