The CaWO4:Eu3+ phosphors with different doping concentrations and different sintered temperatures are synthesized using the microemulsion reaction method. After sintered at different temperatures, the samples with doping concentration of 30 or 50 mol% can obtain the brightest characteristic emissions from Eu3+ ions. At 800 ℃, moreover, the samples with doping concentrations of 0.52 mol% can emit the strongest light. It is therefore concluded that more intense emissions enable the CaWO4:Eu3+ phosphors with high doping concentrations to have great potential to be used as efficient phosphors in the future.