Copolymers of N-alkylacrylamides with acrylamide or methacrylamide derivatives of cholic acid have been prepared to obtain copolymers with desired thermosensitivity and enhanced hydrophilicity. The thermosensitivity of these copolymers depends on their chemical composition as studied by microcalorimetry, differential scanning calorimetry and UV-visible spectroscopy. The lower critical solution temperature and the enthalpy change of the phase separation process of the copolymers in water decreased with increasing content of the bile acid residues in the polymers.