To provide an antiadhesive material strong against physical bending relating to the antiadhesive material, relating to the a flexible antiadhesive material especially excellent in handleability to be more in details.

A water insoluble carboxymethyl pullulan composition is formed by the generation of a hydrogen bond cross-link between molecules through a carboxymethyl group in a molecular chain by carboxymethyl pullulan whose molecular weight is 200,000-500,000 and carboxymethyl group content is 0.5-2.0 mmol/g, wherein the carboxymethyl group is an acid type. The antiadhesive material for which the composition is turned to a film shape is excellent in biocompatibility, in vivo decomposition and absorption occur within appropriate time, the problem of bending which is the fault of a conventional antiadhesive material is solved, and there is almost no influence on a living body.