Abstract: This invention relates to a carbon dioxide absorbing composition including an antisolvent, and to a method and apparatus for absorbing and regenerating carbon dioxide using the same, wherein in a process and apparatus for absorbing carbon dioxide from a gas mixture including carbon dioxide such as a flue gas of a coal-fired power plant and separating a bicarbonate slurry including a large amount of carbon dioxide so as to be regenerated at high pressure, a bicarbonate slurry production yield can be increased to thereby reduce the cost for sensible heat, latent heat and regeneration energy necessary for regeneration, cooling and heating of the carbon dioxide absorbing solution.