An object of the present invention is to provide a solid phase carrier for carrying a bioactive substance, which achieves both the high non-specific adsorption inhibitory effect and high ligand binding amount. Another object of the present invention is to provide a kit for measuring a measurement target substance in a biosample, which includes the solid phase carrier. According to an embodiment of the present invention, a solid phase carrier for carrying a bioactive substance is provided which includes a copolymer present on a surface of the solid phase. The copolymer has a structural unit in which a hydrophilic group and a bioactive substance-reactive group are bonded to an acidic amino acid-derived group through a predetermined linking group.

An object of the present invention is to provide a solid phase carrier for carrying a bioactive substance, which achieves both the high non-specific adsorption inhibitory effect and high ligand binding amount. Another object of the present invention is to provide a kit for measuring a measurement target substance in a biosample, which includes the solid phase carrier. According to an embodiment of the present invention, a solid phase carrier for carrying a bioactive substance is provided which includes a copolymer present on a surface of the solid phase. The copolymer has a structural unit in which a hydrophilic group and a bioactive substance-reactive group are bonded to an acidic amino acid-derived group through a predetermined linking group.