Accurate modeling of the uptake and accumulation behavior of organic contaminants like polycyclic aromatic hydrocarbons(PAHs) in plants is essential to assessing crop contamination and subsequent human exposure.In this study,the performance of a partition-limited model on predicting ryegrass uptake of PAHs(acenaphthene,fluorene,phenanthrene and pyrene) from water was evaluated,and the major influential factors were examined.It was found that model predictions of PAH concentrations in roots and shoots of ryegrass were all within an order of magnitude of the observed values,with the differences between estimated and measured concentrations less than 42.1％ for roots and 78.4％ for shoots.Since the model considered soil/water-plant pathway only,it was inevitable that predictions of PAH concentrations in shoots suffered a bigger error than those in roots due to the influence of foliar uptake,the other important pathway for PAHs.If the impact of foliar uptake was excluded,the accuracy of model predictions of shoot PAH concentrations would be greatly enhanced,with the maximum prediction error reduced from 78.4 ％ down to 47.1％ for pyrene.Other influential factors aside from foliar uptake were also examined,including PAH concentrations in water,uptake time,plant composition and chemical properties.These factors were found to influence the model performance generally through acting on the quasi-equilibrium factor(αpt).Results from this study substantiated the potential application of this partition-limited model for predicting plant PAH concentrations in contaminated sites,and provided some testimony valuable for modification of the model for a better performance.