Crystal growth of Ce 3+ doped LiM(M=Ca, Sr)AlF 6 mixed crystal were successfully carried out in CF 4 atmosphere. The UV absorption spectra and the effective segregation coefficients of Ce 3+ ions in these crystals were measured and reported. Ce∶LiSr 0.8Ca 0.2AlF 6 crystal shows a broaden absorption band in the wavelength range of 240～280 nm, and the effective segregation coefficient of Ce 3+ ions in the mixed crystals is 0.037. It is believed that the broadening of the absorption band in the Ce∶LiSr 0.8Ca 0.2AlF 6 crystal was caused by substitution of Ce 3+ ions for divalent ions in the Colquiriite structure crystals.