CaO sorbent dissolved in chloride molten salts was investigated to identify its CO2 capture property. Various molten salt systems with different melting points (CaCl2, LiCl, LiCl-CaCl2, and LiCl-KCl) were used to control the operation temperature from 450 to 850ºC in order to determine the effect of the operation temperature on the chemical reaction between CaO and CO2. The CaO sorbent showed the best performance at 550ºC in the LiCl-CaCl2 molten salt (conversion ratio of 85.25%). This temperature is lower than typical operation temperature of the solid-state CaO sorbent (~700ºC).