The formation energies, elastic properties, Debye temperature and electronic structure of U-doped ZrO sub(2) within cubic and monoclinic structures are investigated by first-principles approach. The calculated formation energies show that the U-doped with cubic structure is more stable than that of monoclinic structure. The U-doped weakens the resistance to shear deformation whether cubic structure or monoclinic structure. However, the U-doped decreases the shape deformation of cubic structure in contrast to enhances the shape deformation for monoclinic structure. The Debye temperature of U-doped system is lower than the corresponding ZrO sub(2). We found that the calculated electronic structure of these systems are consistent with the variation of formation energies.