[en] An investigation was made into the effect of powerful ultrasonic waves and annealing on structure, magnetic and magnetoelastic properties of metallic glasses on iron and cobalt bases. The alloys under study (Fe₈₁Si₇Bi₁₂Fe₇₈Si₉B₁₂Ni₁, Fe₅₉Si₆B₁₁Co₂₄, Fe₅Co₇₀Si₁₅B₁₀) were produced by quenching from a liquid state and irradiated by focused beam of ultrasonic waves with intensity of 2 kW/cm². The irradiation was found to induce disperse precipitations in the structure of alloys and to change essentially magnetic permeability. Ultrasound had no noticeable effects on coercive force and magnetostriction