There is provided a photocrosslinked polysaccharide exhibiting a low swelling property and a high degradation ability in vivo while retaining a suitable strength. The polysaccharide pseudo-sponge is produced by a crosslinking reaction of a photoreactive polysaccharide obtained by introducing a photoreactive group into a polysaccharide, and exhibits a low swelling property and a blue dextran-low dyeaffinity which satisfy the following properties (I) and (II), respectively: (I) a swelling ratio of not more than 125% as calculated from the values measured by immersing a test specimen having a thickness of 1 mm, a length of 10 mm and a width of 10 mm, and a solvent content of 96% by weight, in water for injection at room temperature for 1 hour, according to the following formula: Swelling€ƒratio = { ( S 2 - S 1 ) / S 1 } × 100 wherein S1 represents an area of the test specimen before the immersion, and S2 is an area of the test specimen after the immersion, in which the area is calculated from the length and width of the test specimen and (II) an absorbance of not more than 0.15 at a wavelength of 620 nm as measured with respect to an aqueous solution containing 0.67% by weight of a polysaccharide which is prepared by immersing a test specimen having a thickness of 1 mm, a length of 20 mm and a width of 10 mm, and a solvent content of 96% by weight, in an aqueous solution containing 0.5 g/mL of blue dextran having a weight-average molecular weight of 2,000,000, and then subjecting the test specimen to water-washing and hydrolysis.
