Abstract：The purpose of this paper was to investigate the effect of microplastics （MPs） on the adsorption of the 16 polycyclic aromatic hydrocarbons （PAHs） in the soils. Through batch experiments， the sorption process of PAHs on polyethylene （PE） and polystyrene （PS） MPs was investigated， and the effects of environmental factors such as pH and humic acid （HA） concentration on the adsorption of PAHs by MPs were systematically evaluated. The results showed that the adsorption kinetics of PAHs on MPs was fitted well with the pseudo-second-order kinetic model. The fitting degree of Freundlich model （R2=0.9868~0.9931） to the adsorption results was significantly higher than that of Langmuir model （R2=0.8638~0.8927）， which indicated that the adsorption process of PAHs on MPs was mainly chemical adsorption. It's calculated by adsorption thermodynamics that the ΔH was positive and the ΔG was negative， which indicated that the adsorption of PAHs was spontaneous and endothermic processes. The pH and HA had a significant effect on the adsorption of PAHs by PE and PS MPs， and the adsorption capacity of PAHs by PE and PS MPs reached the peak at pH 5.0 and pH 7.0， respectively. Additionally， the increasing concentration of HA restrained the sorption of PAHs on PE MPs， and the adsorption amount decreased from 9363.95 ng·g-1 to 4877.42 ng·g-1， but promoted the adsorption of PAHs on PS MPs， and the adsorption amount increased from 9422.71 ng·g-1 to 13259.73 ng·g-1， which indicated that the affinity of PAHs to HA was greater than that of PAHs to PE MPs. Furthermore， the adsorption of the PAHs by MPs were mainly related to electrostatic interaction， π-π interactions， and hydrophobic interaction.