The undoped and Pr3+-doped Fresnoite (Ba2TiSi2O8), Sr-frenoite (Sr2TiSi2O8), and Ge-frenoite (Ba2TiGe2O8) were synthesized by solid-state reaction at high temperature and their photoluminescence properties and electronic structures were investigated. All these undoped samples show luminescence upon UV irradiation at room temperature. The excitation band of intervalence charge transfer (IVCT) emerged only in Sr2TiSi2O8:Pr3+, which was located at 340 nm. Under 340 nm excitation, Sr2TiSi2O8:Pr3+ showed an efficient red emission at 616 nm, ascribing to the 1D2→3H4 transition of Pr3+. However, Pr3+ red emissions and the excitation band of IVCT were not observed for Ba2TiSi2O8 and Ba2TiGe2O8 and the possible reasons for such behaviors were discussed.