A study of Cd²⁺ adsorption of soil samples gathered from the tillage layer(TLLS) and clay layer of Lou soil (CLLS) modified with cetyltrimethylammonium bromide(CTMAB) at various rates and cetyltrimethylammonium bromide + sodium dodecylsulphonate (CTMAB+SDS) mixture was carried out. The results show that in terms of amount of Cd²⁺ adsorbed, a decreasing order of GCK> 50GCB> 120GCS> 100GCB on TLLS and NCK> 50NCB> 100NCB> 120NCS on CLLS, respectively, indicated that the adsorption capacity increased with the rise in temperature;and that a decreasing trend of Cd²⁺ adsorption was quite obvious on modified soils, but not to the extent that the modified soils completely lost their Cd²⁺ adsorption capacities. The Langmuir equation can be used to describe the Cd²⁺ adsorption isotherm. The study of thermodynamic parameters showed that Cd²⁺ adsorption on modified soils was spontaneously controlled by entropy increment, but the capacity property of the soil must be considered simultaneously in discussing the relationship between the adsorption spontaneity and maximal adsorption capacity of Cd²⁺. The analysis of mechanism revealed that modification of the soils was uneven, and that the competition in Cd²⁺ adsorption between the mechanism of cation exchanging adsorption and the mechanism of hydrophobic bonding resulted in the residual adsorption of Cd²⁺ on modified soils. The effect of temperature on Cd²⁺ adsorption was significantly higher in TLLS than in CLLS, indicating that chemical adsorption on TLLS is stronger than that on CLLS.