The process of cadmium adsorption and desorption on lndicotic Black(IB,Cambisols),Yellow Brown(YB,Luvisols)and Red(R,Ferrisols)soils as well as the influence of media's pH were investigated in detail.The presence of organic chemicals obviously influenced the processes of cadmium adsorption and desorption.Adsorption of Cd in YB and IB soils decreased in the presence of citric acid and EDTA,meanwhile,its desorption rate was lower than that obtained in the absence of organic chemicals,which suggests that the relatively unsaturated adsorption sites for Cd increased in the present of organic chemicals.For Red soil,Cd adsorption in the presence of citric acid and ED-TA increased with pH in low pH media but decreased in high pH one,which was very different from YB and IB soils.Further studies indicated that adsorbed Cd in red soil existed significantly as unex-changeable one,and desorption rate by 0.1 mol L^-1 NaNO₃ gave a peak-shape curve.