The Y-Eu oxalate precursor was prepared with a homogeneous precipitation method.And the additives, Na2CO3, S, NaCl or their combination, were introduced into the precursor to prepare Y2O3:Eu3+ red phosphors at 1000～1300 ℃ for 2 h.The effect of molten salts on particle size and luminescent intensity was studied.The experimental results showed that the complex molten salt (Na2CO3+S+NaCl) was conductive to enhance the luminescent intensity of Y2O3:Eu3+.The emission intensity of the phosphor prepared with these additives at 1300 ℃ was about 45% higher than that of the one prepared without molten salt, and about 11% higher than that of the corresponding commercial phosphor.Meanwhile, the particle size of Y2O3:Eu3+ phosphor was controlled effectively with the molten salt.