The leaching behavior of aldicarb among the complex pollution system composed of aldicarb and surfactant-sodium dodecylbenzenesulfonate (SDBS) was studied by soil column. Distilled water was used to simulate rain in order to obtain the rainfall of 235mm for each time. Three simulations were carried out successively to give 705mm rainfall in all. The results of multistep leaching experiment showed that compared with control column, SDBS can increase the vertical distance of aldicarb moving and accelerate the leaching. As the concentration of SDBS increased from 250 to 500mg kg−1 of soil, not only the leaching depth of aldicarb increased by 20cm, but also below 10cm depth in soil column the concentration of aldicarb at the same depth increased obviously. This will enhance the danger of groundwater pollution. SDBS affected the leaching behaviour of aldicarb in soil by influencing its water solubility, adsorption capacity and degradation process. The mechanism of this complex effect has been discussed in this article.