Effect of organic matter, free iron oxide and amorphous Si and Al on the Cd adsorption and desorption of colloids of lime concretion black soil (IBC), yellow brown earth (YBC),red earth (RC) and latosol (LC), which are the typical soils in South and Southeast China,was studied with selective dissolution method. Results showed the decrease of Cd adsorption by colloids of the soils after removal of OM might be due to the decrease of exchangeable adsorption by the soil colloids. Removal of free Fe₂O₃ resulted in significant decrease of Cd adsorption by the colloids of YBC, RC and LC, which indicates the significance of specific adsorption of free iron oxide in these soils. Cd adsorption decreased with increasing of amorphous Al content in soil colloids, which might be due to the high energy exchange sites being occupied by Al ions.The Cd desorption percentage by the soil colloids after different treatmems was in the order: that removing amorphous Si, Al> that removing free Fe₂O₃>that removing OM>the original soil colloids, however, the order differed slightly for different soils under different pH.