Abstract: The large particle neodymium oxide is prepared with oxalic acid as precipitator, and stripping solution by P507-N235-kerosene-cyclohexane system as mother solution. The particle size, morphology, phase composition and thermal stability of samples are characterized by laser particle size analyzers, including SEM, XRD and TG-DTG. The main parameters affecting the particle size of precursor in precipitation are reaction temperature, stirring velocity, feeding speed and aging time. The optimum parameters are as follows: reaction temperature, 50 ℃; stirring velocity, 300 r/min; feeding speed, 9 mL/min; aging time, 24 h. A comparative experiment indicates that the residual organic phase in stripping solution can effectively increase the particle size of precursor. Comparative experiments show that the residual organic phase stripping solution of neodymium oxide effectively increases the particle size of precursor. The precursor decomposes completely to neodymium oxide calcined at 800 ℃ for 2 h. The median particle size of final neodymium oxide is larger than 50 μm.