Crosslinking magnetic thermoresponsive composite (MTC) fiber mats were fabricated by electrospinning process and followed by UV curing. Thermoresponsive poly-(N-isopropylacrylamide) (PNIPAAm) and magnetic Fe3O4 were firstly synthesized by redox-initiated polymerization and co-precipitation, respectively. A crosslinking agent (dipentaerythritol hexylacrylate) and photoinitiator for providing crosslinking ability were then mixed with PNIPAAm and Fe3O4 in ethanol as the electrospinning solution. After electrospinning and subsequent UV irradiation, the MTC fiber mats were thus obtained. Thermoresponsivity of the MTC fibers was measured by both DSC and swelling test. MTC fiber mat exhibited better water-absorption capability and thermoresponsivity than corresponding film. Morphological analysis was observed by SEM and TEM, and the magnetic property was measured by SQUID. The thermoresponsive magnetic behavior of MTC fiber mat in water was observed under various temperatures and magnetic fields. Vitamin B-12 used as a model drug was loaded in the MTC fiber mats and the drug-release behavior was then studied. (C) 2015 Wiley Periodicals, Inc.