PAHs are hydrophobic organic compounds, which have received considerable attention because of their high bioaccumulation, toxicity, carcinogenicity, and mutagenicity. Because of their hydrophobic characteristics, PAHs intent to adsorb on particles, most of PAHs contained in wastewaters are treated biologically, especially in activated sludge systems. But due to the low construction cost and high efficiency, macrophyte-based treatment systems received increasing attention lately. In this work, batch experiments were conducted to study the adsorption behaviors between the aquatic plant (Najas graminea Del.) and PAHs aqueous solutions, including acenaphthene (Acp), fluorene (Flu), phenanthrene (Phe) and pyrene (Pyr). The interactions between different PAHs and if the plant conditions affected the adsorption were also discussed. The kinetic studies showed that the more hydrophobic the PAHs are, the faster the equilibriums achieve, The kinetic constants were found to correlate with Kow. Linear adsorption isotherms were observed in all the adsorption experiments. The adsorption equilibrium constants (K) increase with the Kow indicates that the hydrophobicity of the PAHs dominates the adsorption behaviors. The existence of small mount of Pyr could lower the adsorption of Phe on the plant, while Flu couldn¡¦t. Because the hydrophobicity of Flu is too weak to compete with Phe, so the competition was not observed. The plant after dry process had even better performances in both kinetic and adsorption experiments, which provide more flexibility when put this technology into practice.