The present invention provides a UCST-type thermoresponsive polymer compound which responds to a temperature under physiological conditions and has biofunctionality, and various uses thereof as a thermoresponsive material. Specifically, the invention provides a thermoresponsive material containing, as an active ingredient, a polymer compound represented by Formula (I) below or an addition salt thereof, the thermoresponsive material having an upper critical solution temperature in the range of 5 to 50° C. in an aqueous solution with a salt concentration of at least 1 mM and a pH in the range of 3 to 10.5:wherein m represents an integer of 10 or more n represents a number satisfying 0.4≦n≦1 R1 represents hydrogen or succinyl and R2 represents carbamoyl.
