Provided are a use of chemically-crosslinkable, poly(organophosphazene)s for biomaterials, chemically-crosslinkable poly(organophosphazene)s with a physiologically active substance covalently-bonded thereto, a use thereof for biomaterials, and a process for preparing the same. The chemical crosslinkings can be made by UV irradiation, and/or a crosslinker, and/or an additive, and/or an enzyme, and/or a mixing of at least one polymer.