The present invention aims to provide a biodegradable material having an enhanced shape recovery rate after deformation of the material and an improved flexibility. The present invention provides a biodegradable material which is a chemically cross-linked product between a multivalent compound A having 3 or more functional groups X such as hydroxyl group and a multivalent compound B having 3 or more functional groups Y such as carboxyl group wherein chemical cross-linkage(s) is/are formed by condensation reaction of the functional group(s) X and the functional group(s) Y wherein the value of (y + z)/(x + z) is 1.2 to 4.0 when MA ‰¥ MB, and the value of (x + z)/(y + z) is 1.2 to 4.0 when MA < MB wherein x represents the number of the functional group(s) X which is/are not condensed with the functional group(s) Y y represents the number of the functional group(s) Y which is/are not condensed with the functional group(s) X z represents the number of the cross-linkage(s) MA represents the weight average molecular weight of the multivalent compound A and MB represents the weight average molecular weight of the multivalent compound B.
