There is provided a temperature responsive polymer compound which comprises a repeating unit represented by the following general formula (I): €ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ-R 1 -Hmb-R 2 -€ƒ€ƒ€ƒ€ƒ€ƒ(I) where, Hmb represents a valic acid residue represented by the following formula (II) R 1 represents an amino acid, a polypeptide, or a hydroxy acid being linked by ester bond R 2 represents an amino acid or a polypeptide being linked by amide bond or a hydroxy acid being linked by ester bond: and wherein said polymer compound has 18 or more of amino acids residues and hydroxy acid residues in total.