Abstract: The present invention provides a tissue adhesion prevention material preparable at an affected area at the time of surgical procedure by producing a three-dimensional polymeric structure having a flexible structure and high solute permeability in a medium comprising water as the main component under mild conditions appropriate for body tissue components (i.e., at ordinary temperature and pressure) without conducting a chemical reaction or employing a physical procedure such as heating or light or radiation irradiation. This makes it possible to provide a tissue adhesion prevention material and a joint contracture prevention materials, which can effectively prevent postoperative adhesion of a tissue in the affected area to the surrounding tissue and contracture of the movable part of a joint.