PurposeFew studies have been conducted to understand well the underlying soil sorptive mechanism due to the limited experimental determination for the enormous number of polychlorinated biphenyl (PCB) congeners. The objective of this paper was to obtain further insights into the soil sorption behavior of PCBs with exploration of the sorptive mechanism at the molecular level for sorption affinity, which could be anticipated to help explore the migration fates and assess the bioavailability of PCBs in soil.