Abstract: In this work, numerical simulation and experimental studies are carried out to investigate the distribution of ultrasonic and sonochemical fields in a liquid induced by the direct or indirect irradiation of a point-focusing ultrasound transducer. Results indicate that the sonochemical reaction fields are consistent with the high amplitude acoustical fields by direct irradiation. High amplitude acoustical fields are observed at the focused point and near the liquid surface. The amplitude of acoustical field is decreased at the focused point when indirect irradiation is used. Standing waves are formed between the bottom glass of tube and the transducer. To enhance the pressure amplitude at the focused point, a film is pasted on the bottom of a double-passing tube. In this case, simulation and experiment results indicate that the acoustical pressure in the tube is increased.