Abstract: Nano-CaCO₃ particles were surface-coated with SiO₂ by the sol-gel method and used as the high temperature CO₂ adsorption material.CaCO₃ samples prepared at 60—90℃ were characterized with TEM, EDS and XRD methods and the initial and final decomposition temperature were determined with TGA.The CO₂ adsorption ratio and carbonation-calcination characteristics were evaluated in a φ12 mm fixed bed reactor.The analytical results showed that there was an amorphous SiO₂ film formed on the surface of nano-CaCO₃,and the atomic ratio of Si to Ca is 1∶39.The initial and final decomposition temperatures were 595—620℃ and 800—820℃ respectively.The maximum CO₂ adsorption ratio of SiO₂ coated with nano-CaCO₃ was 92.1% at 600℃with a 10% increase as compared with the uncoated nano-CaCO₃ particles.After 20 cyclic carbonation and calcination runs, CO₂ adsorption ratio of the SiO₂ coated samples was 63%.The XRD analysis illustrated that the crystal type of nano-CaCO₃ had no change after 20 cyclic runs.