The dependence of initial susceptibility X on applied tensile/compressive stress sigma has been determined for Fe and Co based amorphous alloys characterized by positive and negative magnetostriction, respectively. The contributions to X originating from coherent spin rotation (X/sub r/) and domain wall motion (X/sub w/) are separated by means of suitably devised experiments and found to correlate with the evolution of the domain structure vs. sigma , as directly verified by means of magnetooptical Kerr effect observations. High tensile stresses produce entirely longitudinal (transverse) domain structure in Fe (Co) based ribbons. The longitudinal (transverse) pattern evolves into a transversal (longitudinal) one by progressively changing tension into compression. X/sub r/ and X/sub w/ correspondingly pass through a maximum at intermediate stress values. >