An incubation experiment was conducted to study immobilization of arsenic in mining area soil by two kinds of material,namely,iron-containing materials(Fe2O3,Fe2(SO4)3) and rare-earth materials(CeCl3,LaCl3).The results showed that Fe2O3 had little effect on immobilization of soil arsenic,attaining only 3.81% decrease in exchangeable arsenic at an application of 8 g/kg(Fe).On the contrary,the other three materials proved to be effective in immobilizing arsenic.Fe2(SO4)3 was the most effective as well as LaCl...