Provided are a novel carboxymethyl cellulose (CMC) structure and a method for producing the same. The CMC structure of the present invention is useful as a medical material and particularly as an adhesion-preventing material, and has good biocompatibility and bioabsorbability and controllable periods of functioning and dissolving, or has both effects for preventing adhesions and wound healing.The CMC structure of the present invention is substantially composed of carboxymethyl celluloses, comprising an acid carboxymethyl cellulose and an alkaline metal carboxymethyl cellulose in a mixed state. The method of production of the present invention comprises subjecting the alkaline metal (or acid) carboxymethyl cellulose structure to an acid (or alkali) treatment, wherein the acid (or alkali) treatment is terminated before the alkaline metal (or acid) carboxymethyl cellulose is fully converted to the acid (or alkaline metal) carboxymethyl cellulose.