The alloying effect of the refractory elements Ta and W on the electronic structure of y-TA is investigated by using the first-principles discrete variational method within the framework of density functional theory. The impurity formation energy result indicates that Ta and W can stay steadily in the TiAl system by way of substitution. The Mulliken population, density of states and charge density difference results show that Ta and W both give rise to the strong interaction between themselves and the neighboring host atoms. The alloying effect of the two elements onγ-TiAl is the same. The alloying effect of the refractory elements Ta and W on the electronic structure of yT A is investigated by using the first-principles discrete variational method within the framework of density functional theory. The impurity formation energy result indicates that Ta and W can stay steadily in the TiAl system by way of substitution. The Mulliken population, density of states and charge density difference results show that Ta and W both give rise to the strong interaction between themselves and the connected host atoms. The alloying effect of the two elements onγ-TiAl is the same.