The thermoresponsive polymer poly(N-isopropylacrylamide) was immobilized in a specific pattern on a polystyrene matrix by photolithography. N-Isopropylacrylamide was copolymerized with acrylic acid. The copolymer was coupled with azidoaniline. The low critical solution temperature of the copolymer was lowered by incorporation of azidophenyl groups. The derivatized copolymer was then immobilized on a polystyrene matrix. The surface wettability of the immobilized polystyrene matrix changed with temperature, whereas that of untreated polystyrene matrix was insensitive to temperature. The measurement of contact angle showed that the surface of the immobilized matrix was hydrophobic at 37 degrees C but hydrophilic at 10 degrees C. Micropatterned immobilization of the copolymer on the polystyrene matrix surface was carried out using a photomask. The surface micropattern was clearly observed by phase-contrast microscopy at 37 degrees C. At low temperatures, hydration of graft chains erased the micropattern. The polystyrene matrix with micropatterned surface was applied to tissue engineering. Mouse fibroblast STO cells grown on the surface area, on which thermosensitive polymers were immobilized, were selectively detached by lowering the temperature.