The hydrogen sulfide and the ammonia are generated in large amount at leather processing plant, sanitary station and waste water treatment. Among various odor removal techniques, the adsorption has an advantage in removing non-continuous, high concentration gases. To increase the removal efficiency at low cost, the activated carbon was impregnated with KCl, NaOH, KI to remove hydrogen sulfide, and it was impregnated with HNO₃, H₂SO₄ to remove ammonia. Activated carbon with KI showed highest removal efficiency of hydrogen sulfide, and indicated 78% of removal efficiency after 4 cycles of regeneration. Activated carbon with H₂SO₄ showed higher removal efficiency of ammonia among solution test, however, it was not satisfactory.