The condensed adamantane (C10H16) is the smallest member consisting of one diamond-structure-like used for lightemitting devices. We have simulated the electronic structure of C10H16 by discrete variational (DV)-Xα molecular orbital method. The 26(Td) high symmetries of C10H16 cluster models were designed by using 216 space group and used lattice parameter of diamond. The cluster models, radial function, energy levels, density of states, bond overlap and contour map were simulated and analyzed. It was found that the energy levels and density of states obtained the value of energy gap about of 6.25eV, agree with literature data. The bond overlap population has bonding and antibonding of atom interaction in cluster model and contour map of HOMO and LUMO.