Abstract: Synthesis of CaTiO₃:Pr³⁺ red long afterglow phosphor with different Pr³⁺ molar ratio by flux fusion method were presented. Their afterglow decay curves were measured. The afterglow time is over 40 min with Pr³⁺ 0.1%. With the increase of Pr³⁺ molar ratio, the afterglow time deteriorates rapidly. The initial brightness is associated with Pr³⁺ molar ratio, with Pr³⁺ 0.2%, the phosphor gets the highest initial brightness. The excitation spectra and emission spectra were measured. The emission peak is at 613nm which is ascribed to the energy transition of ¹D₂-³H₄. Due to the function of weak crystal field, the main emission divides into 612nm and 614nm. Besides the main emission peak, phosphor has a shoulder emission peak at 620-628nm. Alteration of Pr³⁺ molar ratio has little effect on the emission spectra, but with Pr³⁺ 0.2%, phosphor gets a emission peak at 626nm. The excitation peak is at 342nm, with a shoulder peak at 400nm. The thermoluminescence glow curves of-phosphor were measured. The phosphor has three thermal peaks at 150K, 250K and 330K. With the increase of Pr³⁺ molar ratio, the thermal peak at 330K deteriorates distinctly. The afterglow characteristic of phosphor is associated with the thermal peak at 330K.