The SrTiO3∶Pr3+material, co-doped with monovalent Li+, divalent Mg2+, and trivalent Al3+ was prepared by a new sol-gel method. The phase and crystallinity of the synthesized materials were investigated by powder X-ray diffraction(XRD) and scanning electron microcopy(SEM). Among the co-doped ion, Al3+incorporation caused the least lattice change and had the best crystallinity. Photoluminescence spectra were taken to investigate the luminescence characteristics. We observed a red luminescence change of SrTiO3∶Pr3+after being co-doped, and a best enhancement on the red luminescence with the trivalent Al3+ was observed. The present results indicated that the charge defect associated with Al3+has led to charge compensation of Pr+Srand also implied that the charge defects(usually the second dopant ions replacing the A or B sites in the lattice) which are closer to Pr+Srcontribute more to the red luminescence enhancement.