Abstract: CeO₂ precursors were prepared by the homogeneous precipitation method, hydrothermal synthesis method and hydrothermal precipitation coupling method using urea as a precipitator.The results indicated that urea was a reserve resource of CO^2-₃.CeO₂ precursors were orthorhombic Ce₂O(CO₃)₂·H₂O, hexagonal Ce(OH)(CO₃), orthorhombic CeO(CO₃)₂·H₂O respectively when the homogeneous precipitation method, hydrothermal synthesis method and hydrothermal precipitation coupling method were used.The synthesis technology had a great effect on the precursors.Different precursors were synthesized through various processes and mechanisms.When heated up to the temperature of 500℃, the precursors were all finally changed into face centred cubic CeO₂ powders.