Under the mixed mode loading, it has been known that the influence of non-singular terms in the stress fields is serious, because the critical distance, γ_o - the distance of nonlinear elastic region near the crack tip has no negligible value. In this paper, it has been studied on the influence of non-singular terms, T-stress, and the case of T=0, σcos²β, σcos(2β) and 0.05 σcos(2β), under uniaxial tension and compression. It has been seen that the T-stress of σcos(2β) has better than others as comparing to the experimental data.