Abstract: The adsorption characteristics of As₂O₃(g) by CaO, Fe₂O₃, MgO, Al₂O₃, K₂SO₄ and Ca/Fe mixed adsorbents under the simulated flue gas atmosphere were studied by using a gas phase arsenic adsorption reaction experimental device at temperatures between 300 and 900℃. The results indicate that the adsorption ability of CaO is the strongest among the five single element adsorbents, while K₂SO₄ is the weakest. With the increase of temperature, the adsorption amount of CaO increases first, decreases slightly at 700℃, and then increases, while the adsorption amount of Fe₂O₃ increases first, and then decreases. However, the adsorption amount of MgO, Al₂O₃ and K₂SO₄ increases all the way. Compared with the calculated values of adsorption amounts of Ca/Fe mixed adsorbents in three proportions, the experimental values increase by 92% at least. The adsorption effect is the best when the ratio of CaO to Fe₂O₃ is 3:1. And the change of surface structure caused by sintering reaction after mixing is an important reason for the improvement of the adsorption effect.