An ethyl-vinyl acetate copolymer (EVA) preirradiation-grafted with N-isopropylacrylamide (NIPAAm) was prepared. Various methods which can be used to control the grafting reaction are described. DSC and TMA were employed to characterize the surface thermosensitivity of the graft copolymer. It is indicated that the surface of EVA grafted with NIPAAm shows thermosensitivity similar to a partially crosslinked poly-NIPAAm (PNIPAAm) gel. The response to the change of temperature through the lower critical solution temperature (LCST) of the graft was swifter than that of the PNIPAAm gel. SEM revealed a micropore structure in the surface layer of the sample. DSC was also used to analyze the water state in the surface layer of the sample.