A series of LiGa5－xSixO ₈:0.5%Cr³⁺(x=0,0.1,0.25,0.5,0.75) near-infrared persistent phosphors were successfully prepared by the high-temperature solid state reaction method in ai r.The luminescence properties and the afterglow behaviors of phosphors were investigated in details.The results indic ate that these phosphors exhibit near -infrared long afterglow emission centered at 717nm due to the ²E→⁴A₂ transiti on of Cr³⁺ ions.The incorporation of Si⁴⁺ significantly improves the persistent luminescence performance of pho sphors.The optimized persistent performance and the strongest luminescence intensity could be obtained when the doping content of Si⁴⁺ in LiGa₅O₈:Cr³⁺ is experimentally about 0.25.The afterglow can last for a pproximately about 30h. Thermoluminescence spectra indicate that the incorporation of Si⁴⁺ contrib utes to the formation of defects and increases the number of traps,thus improving the persistent luminescence properties of ph osphors.