Abstract: A method of vitrifying a high-level radioactive liquid waste comprising removing a precipitate composed mainly of Mo and Zr from the high-level liquid waste, mixing the resulting high-level liquid waste with a raw glass material having a chemical composition wherein the B.sub.2 O.sub.3 /SiO.sub.2, ZnO/Li.sub.2 O and Al.sub.2 O.sub.3 /Li.sub.2 O ratios are at least 0.41, at least 1.00 and at least 2.58, respectively, and melt-solidifying the mixture to thereby form a vitrified waste. By using such a raw glass material, there can be obtained a vitrifled waste having the waste content of about 45% by oxide weight in which the same leaching rate as that of a conventional vitrified waste having the waste content of 25% by oxide weight is ensured without suffering from yellow phase separation.