PROBLEM TO BE SOLVED: To provide a photocrosslinked hyaluronic acid excellent in barrier effect and degradability which are necessary characteristics as medical materials, and a medical material including the same.SOLUTION: The photocrosslinked hyaluronic acid is obtained by optically irradiating a photoreactive hyaluronic acid in which hyaluronic acid and a glycidyl ester represented by general formula (1) are covalently bonded. The photocrosslinked hyaluronic acid has a cyclobutane ring formed by mutually crosslinking unsaturated carbon double bonds that are photoreactive groups of glycidyl ester of a photoreactive compound covalently bonded to the photoreactive hyaluronic acid, and has a network structure. (In the formula, R-CO- each represents a photoreactive residue of the photoreactive compound having carboxyl and unsaturated carbon double bonds in the molecule, and the photoreactive compound is cinnamic acid, thiophene acrylic acid, cinnamylidene acetic acid or sorbic acid).