The FP-LAPW method is employed and the gradient generalized approximation (GGA) is used to treat the exchange-correlation potential. In this study we considered the Al3Ti0.5V0.5 alloy case. In which we investigated the structural stability of the tetragonal D022 and cubic L12 ternary alloy Al3Ti0.5V0.5 relative to the Al3Ti and Al3V. The total energy calculation as a function of its volume shows that the tetragonal phase is the more stable one. The formation enthalpies are calculated. The total and partial density of states exhibits a deeppseudo gap near the Fermi level and the transition metal contribution to the DOS is almost entirely formed by the d-electrons.