xPr3+-activated 43SiO2-23Al2O3-27LiF-17YF3 (x=0.1、0.2、0.3、0.4 ) (mol%) glass were synthesized by a conventional melting technique, and then annealed at 530℃, 540℃ and 550℃, respectively. Transparent LiYF4: Pr3+glass ceramics were successfully prepared. X-ray diffraction and transmission electron microscope were used to monitor the crystalline phase structure after the glass specimens were annealed at temperature increasing from 530℃ to 550℃, the average size of nanocrystals in glass ceramics was 14±4 nm. The UV-visible spectra were used to monitor the transparency remained at a high level. The spectral properties and lifetime of glass and glass ceramics were investigated. The parameters of LED also be investigated. Under 404 nm excitation, the glass ceramics which doped 0.3 mol Pr3+ion and heated at 550℃ had the highest light output intensity, when it was made into LED, it produced white light. The calculated color coordinates of the LED was located in x=0.33,y=0.35.