Abstract: Ultrasound velocities as the functions of the bias magnetic field and annealing temperature were investigated in the Fe_72.5Cu₁Nb₄Sil_3.5B₉ alloy. The samples were annealed in vacuum for 1 h in the temperature range from 200 to 700^oC The maximum changes were observed after annealing at the temperature of 450^oC when the magnetomechanical coupling coefficient reached maximum value (k = 0.62). The ultrasound velocities were ehanging from 3.5 to 5.3 km/s depending on the magnetic bias field and the thermal-treatment history.