[en] The compound and method for solidification of high-level radioactive wastes are suggested. Compound on the basis of the polymeric phosphate glass with the formula M₃P₇O₂2 or M(PO₃)₃. (M is the trivalent metal, namely Al, In or Hf) is used. The method comprises preparation of a melt of the compound which is the forerunner of used phosphate glass with the formula M(H₂PO₄)₃, introduction into the melt of solid wastes (4-47 mass%), the mixture heating, its keeping at the temperature of 1200-1500 deg C to obtain the required polimerization degree, formation of blocks of the melt and their cooling. Data, characterizing the composition of forerunner-compound crystals and effect of various factors on the properties of the product, obtained as a result of the suggested method use are presented. The conclusion is made, that the method suggested ensures long-term and safe storage of solidified radioactive wastes