Thermosensitive poly(N-isopropylacrylamide) (PNIPAM) composite exhibit a unique phase change at its lower critical solution temperature (LCST). The properties of PNIPAM nanocomposite make it a good candidate material for many applications, such as in articial muscles, drug delivery system, reversible surfaces, separation membranes, enzyme immobilization, catalysis substrates, actuators, and chemical valves. Thermal responsive composite were synthesized by two step. In the first step, N-isopropylacrylamide and methylene bisacrylamide as crosslinking agent was copolymerized at 65 ℃ and generated the silica in PNIPAM network by in-situ precipitation method as second step. Hydrogel containing silica exhibited a LCST similar to PNIPAM hydrogel. However, tensile strength showed that the mechanical property of thermoresponsive PNIPAM composites was improved compared to PNIPAM without silica filler.