[en] The author introduces changes of existing state of uranium in principle rock-forming minerals during alkali metasomatism using fission-track method. Research results show that uranium content in main rock-forming minerals significantly decreases, and most uranium-bearing accessory minerals disappear, and uranium is removed from the rock after alkali metasomatism. Authors suggest that fission-track method may be directly and quantitatively applied to the research on the migration of ore-forming elements in minerals