The present invention relates to a biodegradable and thermosensitivepoly(organophosphazene) with a functional group, a preparation method thereof,and a use thereof for delivery of bioactive substances. According to thepresent invention, poly(organophosphazene) is a phosphagen-based polymershowing biodegradability, thermosensitivity, and sol-gel phase transitiondepending on temperature change, whereby when administered into a living bodywith bioactive substances such as drugs, the poly(organophosphazene) forms agel-phase at body temperature to be capable of controlled release of thebioactive substances. Further, the poly(organophosphazene) has functionalgroups to chemically bind with bioactive substances through an ionic bond,covalent bond, or coordinate covalent bond to be capable of a sustainedrelease of the bioactive substances due to its good binding property.Therefore, the poly(organophosphazene) is useful as a delivery material forbioactive substances.
