The embodiments of the present disclosure relate to a carbon dioxide absorbent containing an ionic material containing a cyclic ammonium cation and a hydroxide anion. The carbon dioxide absorbent according to an embodiment contains a hydroxide anion having a small molecular weight and high basicity, such that absorption performance per unit volume of the absorbent may be effectively improved. Further, the carbon dioxide absorbent according to an embodiment is soluble in water and thus may not cause layer separation problems.