Abstract:To explore stabilization effects of calcium carbonate for Pb, Zn and Cd in contaminated soil, taking heavy metal (such as Pb, Zn and Cd) compound contaminated soils in Baiyin Dongdagou of Gansu province as research object, adding different amounts of calcium carbonate conducted stabilization experiments. The results show that the pH increased from original 7.45 to 7.91 and the leaching concentration decreased gradually; the stabilization efficiency of Pb, Zn reached maximumly 50.75% 、51.18% respectively with horizontal vibration method and 55.19%、21.40% respectively with sulphuric acid & nitric acid method when the addition amount of calcium carbonate were increased from 1% to 15% in lightly contaminated soil. The pH increased from original 6.76 to 7.16 and the leaching concentration decreased gradually; the stabilization efficiency of Pb, Zn and Cd reached maximumly 75.82%、74.21%、99.19% respectively with horizontal vibration method and 26.75%、65.55%、78.39% respectively with sulphuric acid & nitric acid method when the addition amount of calcium carbonate were increased from 2% to 18% in the heavily contaminated soil. The slight increasing of pH after adding calcium carbonate is that calcium carbonate will dissolve and generate OH- in soil solution, heavy metals may be formed?hydroxide and carbonate precipitation, thus reduced effectively the migration of heavy metals and had the stabilization of heavy metals.