Modification of the surface of polyethylene film was performed in aqueous organic solvents in the presence of horseradish peroxidase. The affecting factors such as solvents composition, initiator, reaction time and reaction temperature were investigated. It was found that the grafting efficiency is higher in dioxane than that in the other solvents used and the initiators substituted by electron donating group facilitates the grafting reaction. And the optimum reaction condition was determined to be reacting in the 40% dioxane solution at 40 degrees C for 2 hours. The treated film was characterized with scanning electron microscopy (SEM), UV-Vis spectra, FT-IR, and contact angle measurements. Polar groups such as -CO and -NH2 were found to appear on the treated surface and the surface of treated film become rougher than the untreated film. The contact angle with water decreased from 80 to 50 and the absorption of the treated film in ultraviolet area increased significantly, which indicates that the hydrophilicity of PE film had been increased.