The article studied the effects of decomposition products of organic materials(grass charcoal,pig manure,earthworm manure) on adsorption of Cd2 .The results showed that the Langmuir equation could be used to describe the Cd2 adsorption isotherm.The adsorption of Cd2 was about to increase,as temperature adding.The study of thermodynamic parameters showed hat adsorption on modified soils was spontaneously controlled by entropy increment.The effect order of organic materials on adsorption capacity of Cd2 was insoluble decomposition product >soluble decomposition product;grass charcoal decomposition product >pig manure decomposition product>earthworm manure decomposition product>CK.