Chemical modification of the surface of low-density polyethylene (LDPE) film was performed with an aqueous solution of ammoniacal ammonium persulfate in the presence of Ni2+ ions, where the polar groups were generated on the surface of the LDPE film. The surface of the LDPE film was modified chemically with an ammoniacal solution of ammonium persulfate (1.1M) and Ni(SO4)(2) (0.02M) heated at about 70 degreesC for 3 h. The morphologies of the surfaces were studied with scanning electron microscopy and infrared spectroscopy; electron spectroscopy for chemical analysis revealed the introduction of polar groups on the surface, which improved printability and adhesion properties.