A sonochemical reaction field in a rectangular glass cell driven by two kinds of ultrasonic transducer was visualized optically and compared with a distribution of multi-bubble sonoluminescence. Fluid motion in the cell was measured using a laser Doppler velocimeter. In a standing-wave type reactor driven at 140 kHz, the reaction field formed layers and was not uniform accompanying fluid motion at high intensity. In a horn-type reactor of 19.5 kHz, the luminescing region was confined in very close vicinity to the horn tip in contrast with broad region of fast fluid motion. ©2000 American Institute of Physics.