A stimulus-responsive material comprising a stimulus-responsive polymer, fibers, and water, wherein the number average diameter of the fibers is 1 to 900 nm, and the fibers are dispersed. Also, medical materials and anti-adhesion treatments using stimuli-responsive materials comprising stimuli-responsive polymers, fibers, and water, the fibers having a number average diameter of 1 to 900 nm, and the fibers are dispersed. Wood. Provided is a stimulus-responsive material that is improved in convenience of application and has both required mechanical properties during coating and required properties (for example, biodegradability, biocompatibility, low toxicity, etc.) according to various uses.刺激応答性高分子と繊維と水からなり、繊維の数平均直径は１～９００ｎｍであって、かつ、繊維は分散して存在していることを特徴とする刺激応答性材料。また、刺激応答性高分子と繊維と水からなり、繊維の数平均直径は１～９００ｎｍであって、かつ、繊維は分散して存在している刺激応答性材料を用いた医療材料および癒着防止材。適用利便性が向上され、被覆時の力学特性や各種用途に応じた要求特性（例えば、生分解性、生体適合性、低毒性等）を両立する、刺激応答性材料を提供する。
