This study developed a new model to estimate the ER of PAHs. A strategy to evaluate the potential NPS loading of PAHs at a water-shed scale was also proposed. The ER model, while incorporating the fugacity concept, explicitly considers the transport of major doil adsorbents in the runoff and erosion processes. Lts applicability was examined With Experimental data. The modeling uncertainty was also assessed, which enhanced our understandings on the model's applicability and the compound-dependent enrichment behavior of PAHs. The results of this study are of great importance to the model innovationand environmental management practices regarding the PAHs (probably other chemicals alike as well) pollution.