It is estimated that the uranium-oxygen bond dissociation energy(Du4_-O~+=l465.38kJ/mol) is higher than silicon-and aluminium-oxygen bond dissociation energies(Dsi4_-O~+=1264.41kJ/mol and D_Al3_-O~+=1105.32kJ/mol). During the process of magmaticdifferentiation with increasing degree of polymerization for silicon-oxygen complex ion,uranium in granitic melts tends to combine with oxygen to form the coordination polyhedron[UO_x~(2x-n)] and to occur in the form of nuelei and crystals of uraninite, as has been demonstratedby the induced fission-track study of quartz syenite from Huangmeijian. It is estimated that the uranium-oxygen bond dissociation energies (Du4_-O ~ + = 1465.38 kJ / mol) are higher than those of silicon-and aluminum-oxygen bonds dissociation energies (Dsi4_O ~ + = 1264.41 kJ / mol and D_Al3_- O ~ + = 1105.32 kJ / mol). During the process of magmatic differentiation with increasing degree of polymerization for silicon-oxygen complex ion, uranium in granitic melts tends to combine with oxygen to form the coordination polyhedron [UO_x ~ (2x-n)] and to occur in the form of nuelei and crystals of uraninite, as has been demonstrated by the induced fission-track study of quartz syenite from Huangmeijian.