The effects of a mixed solvent consisting of water and organic solvents such as acetone and methanol on the photografting (lambda > 300 nm) of N-isopropylacrylamide (NIPAAm) on linear low-density polyethylene film (thickness = 30 mum) was investigated at 30degreesC and 60degreesC. Xanthone, which had been coated on the film, was used as a photoinitiator. The photografting initiated even in the system at 30degreesC by using a longer irradiation time. It was found that the maximum percentage of grafting was attained at a certain concentration of organic solvent in the mixed solvent, which shifted to a lower concentration of organic solvent in the system at 60degreesC compared with the system at 30degreesC. It was found that the grafted chains of the sample prepared in the system with the higher polymerization temperature and the use of mixed solvent penetrated into the center of the film compared with the sample prepared in the system with the lower polymerization temperature and use of a water solvent. Moreover, the NIPAAm-grafted films exhibited temperature responsiveness, swelling and shrinking in water at 0degreesC and 50degreesC, respectively. The extent of this characteristic was found to be closely related to the location of the grafted chains in film substrate, which was measured by an attenuated total reflection infrared spectroscope and a scanning electron microscope.