Abstract: Ab initio calculations of structural, electronic and energetic properties for pure α-Zr with different concentrations of isolated vacancy were made by using software packages Wien2 k. The lattice constant change in the pure α-Zr with different concentrations of isolated vacancy was obtained, and its electronic density, density of states, and band structure were calculated. The results show that an increase in the concentration of the isolated vacancies in the pure α-Zr leads to the decreasing of the values of the lattice constants. The electronic density of an atom which has a vacancy as a first-nearest neighbor becomes stretched in the direction of neighboring atoms, whereas the electronic density of those atoms, which have zirconium atoms, as first-nearest neighbor, remains symmetric. With the decreasing of the concentration of the isolated vacancy inside the unit cell, the height of main peaks of total density of states increases, and the band structures become more complicated.