A method was developed to prepare thermosensitive poly(N-isopropylacrylamide) (PNIPAAm) hydrogels with an interpenetratingpolymer network (IPN) structure for the purpose of improving its mechanical properties, response rate to temperature andsustained release of drugs. Although the differential scanning calorimetry data exhibited similarly lower critical solution temperature(LCST) between IPN- and non-IPN–PNIPAAm hydrogels, an increase in the glass transition temperature (Tg) ofthe IPNs relativeto the normal PNIPAAm hydrogel was observed. In addition, the mechanical properties ofthe IPNs were greatly improved whencompared with the normal PNIPAAm hydrogel. The interior morphology ofthe IPN–PNIPAAm hydrogels was revealed byscanning electron microscopy (SEM); the IPN hydrogels showed a fibrillar-like porous network structure that normal PNIPAAmdid not have. Furthermore, by measuring the temperature dependence ofthe swelling ratio and deswelling kinetics, these IPNhydrogels also exhibited improved intelligent characteristics (e.g., controllable faster response rate) that depended on thecomposition ratio of the two network components. From the applications viewpoint, the effects of a shrinking–reswelling cyclearound the LCST on the properties ofthe IPN hydrogels were examined to determine ifthese properties would be stable forpotential applications. Bovine serum albumin was chosen as the model protein for examining its release from the IPNs at differenttemperatures. The release data suggested that an improved controlled release could be achieved by the IPN–PNIPAAm hydrogelswithout losing their intelligent properties.