An approach to model nucleation induced by power ultrasound during crystallization is developed in this work. The approach is based on the assumption of heterogeneous nucleation mechanism: During the ultrasound burst, an extended nucleation kinetic expres- sion is applied. The simulation results show a qualitative agreement with the experimental observations: An optimal condition of using ultrasound during crystallization to achieve a narrow CSD turns out to depend strongly on the supersaturation ratio at which the ultra- sound is applied.