A first-principles investigation for disodium oxide in a cubic lattice with Na+ defect, Face center defect, Na+ and O- vacancy, has been carried out by the PWscf (plane-wave selfconsistent field) approach with standard local-density approximation (LDA) and generalized gradient approximation (GGA). The total energy, lattice constant, volume variations, cation defect, anion defect, vacancy defect and vacancy energy formation are calculated with relaxed supercell structure 1x1x1 of disodium oxide.The calculated total energy increases by increasing vacancy in supercell structure. O- vacancy formation energy is higher than the Na+ vacancy formation energy.