Poly[N-isopropylacrylamide-co-(maleic acid)], poly(NIPA-co-MA), was synthesized by radical polymerization in an aqueous solution composing of 35% mol N-isopropylacrylamide/maleic acid. Poly(NIPA-co-MA) hydrogel nanofibrous membrane was fabricated by electrospinning using ethanol as solvent. The electrospun nanofibers were cross-linked using diethylene glycol as cross-linker, followed by a heat-induced esterification reaction at 145 degrees C. The average diameter of electrospun fibers was 117 +/- 33 nm. The hydrogel membrane exhibited a temperature sensitive property. Its minimum and maximum water absorption ratios were 4 +/- 0 g g(-1) at 50 degrees C and 17 +/- 4 g g(-1) at 34 degrees C, respectively. An equilibrium swelling state of the electrospun membrane was reached within 5 min.