Vaterite nano-sized CaCO₃ with elipse ball-like were prepared by carbonization method of CO₂ using calcium oxide as the raw material in none water system.The influences of operation parameters such as carbonization temperature,the amount of calcium oxide,CO₂ flow velocity and the different kinds of solvents on the crystalline form and particle morphology of CaCO₃ were explored and the process conditions were optimized.The products were characterized by XRD,SEM,FT-IR and TEM.And the formation mechanism was also discussed.Results showed that the morphology of nano-sized calcium carbonate was affeced by the above four factors,while the carbonization temperature had a greater influence.The elipse ball-like calcium carbonate particles with vaterite crystalline form was prepared under the optimum conditions as follows：the carbonization temperature of 5 ℃,the amount of calcium oxide of 2.8 g in 100 mL methanol and the CO₂ flow velocity of 100 mL/min.