Photosensitive monomer 4,5-dimethyl-2-nitrobenzene methacrylate(DMNBMA) was grafted onto the surface of polyethylene (PE) film by pre-irradiation grafting method. The kinetics of the irradiation graft polymerization, such as the effects of absorbed dose, reaction time, reaction temperature, and monomer concentration on the degree of grafting were studied. FT-IR analysis was used to investigate the chemical structure of the grafted film and the results showed that DMNBMA was grafted onto PE film successfully. The grafted film was exposed under UV irradiation to initiate the photodecomposition reaction and the ester groups of the graft chains converted into carboxyl groups which made the hydrophobic surface become hydrophilic. The results of photodecomposition reaction demonstrated the PE film was photosensitized by grafting with 4,5-dimethyl-2-nitrobenzene methacrylate.Cited