The coloration of fluorite would be improved by doping impurity ions Li+, Na+, K+, Which may serve as a basic working material of tunable color-center laser probally operating at room temperature, and as a result, causes extensive attention. Some works on how to increase the concentration of Li+, Na+, or K+ in CaF2 crystal, such as preparation of raw materials, method for crystatal growth, test of crystal deffection, determination of impurity concentration and so on, were carried out and the preliminary results achieved are the following.Four different raw materials were prepared:(1)purified natural flurite with good quality which is proportionally mixed with the eommercial reagents of LiF, NaF and KF as normal powder;(2)the mixed material of synthetic crystals of LiF, NaF and CaF2;(3)chemically eopreeipitated material;(4)solid-phase reaction material. Using the graphite crucible depression method, contrast experiments of gas-free-filling for the crystal growth of the four raw materials described above indicate that the impurities in the crystals growing with normal fine powder is the lowest and impurity content in the crystals growing with crystal fine powder are slightly improved while the crystals obtained with chemically eopreeipitated and solid-phase reaction material are better. The single crystals in size of 10?60 mm more transparent are demonstrated in photo 1. The concentration of impurities in the doped CaF2:Na+ was measured by atomic absorption spectroscope, the content of NaF being of 0.1-0.4%(Mol).