Abstract: Longitudinally driven giant magneto-impedance (LDGMI) effect of high frequency is measured for Fe₇₃Cu₁Nb_1.5V₂Si_13.5B₉ nanocrystalline ribbons annealed under different tensile stress. It can be concluded from the field dependence of phase that imaginary part of permeability μ", which is corresponding to the magnetic losses, plays an important role in the high frequency LDGMI effect, and that the value of transverse magnetic anisotropy field H k can be easily determined by the minimum of the field dependence of phase. It provided a kind of new method to measure the magnetic anisotropy field.