Abstract: Provided are carbon dioxide capture composite particles which contribute to carbon neutrality by fixing carbon dioxide in seawater or an aqueous solution in which calcium ions are dissolved through mineralization, and a method of producing the same. More particularly, provided are carbon dioxide capture composite particles which capture carbon dioxide in seawater to form calcium carbonate particles, preferably aragonite type calcium carbonate, and a method of producing the same. In an exemplary embodiment, a method of producing carbon dioxide capture composite particles including: immersing polyamidoamine particles in seawater or an aqueous solution in which calcium ions are dissolved and maintaining the solution at room temperature under normal pressure to produce carbon dioxide capture composite particles in which aragonite type calcium carbonate particles are formed on a surface of the polyamidoamine particles is provided.