Abstract: To perfect the structural mechanism of magnetic anisotropy induced by tensile stress,a series of Fe_73.5Cu₁Nb₃Si_13.5B₉ nano-crystalline alloy ribbons were prepared with TSADP(tensile stress annealing at different phases) method.The longitudinal driven giant magneto-impedance(LDGMI) effect of samples were measured by HP4294 A impedance analyzer.Meanwhile,the mesoscopic and magnetic structures in cross-section of sample S₅,which applied tensile stress for whole annealing process were observed by P47 H atomic force microscope(AFM).Resultsshow that the maximum value of H_k is obtained in sample S₃,which applied tensile stress annealed keep in 550℃ for one hour.There is a particular phenomenon that an angle α(0°≤α≤90°) exists between the directional ordering cluster and external tensile stress axis direction in cross-section,and which has stripe domain structures.A model of particles cluster is proposed in this paper.The idea that transverse magnetic anisotropy induced by tensile stress annealing at different phases may be originated from magnetic exchange coupling effect of directional ordering of particles cluster,are suggested.