CsPbBr3 quantum dots were precipitated in phosphate glasses through heat treatment. Controlled formation of CsPbBr3 quantum dots was realized by adjustment of heat-treatment conditions. Absorption and photoluminescence spectra of CsPbBr3 quantum dots were tuned from 432 to 521 nm. Upon ultraviolet or blue light excitation, efficient photoluminescence from these CsPbBr3 quantum dots doped phosphate glasses was observed.