Abstract: The dependence of sonochemical yield produced by 28kHz ultrasound on sound intensity and sonication time has been studied by using iodine release method in this paper. It has been shown that the sonochemical yield varies nonlinearly with sound intensity and linearly with sonication time. We have further studied the sonochemical yield by a combining orthogonal ultrasonic irradiation system at frequencies of 28kHz and 1.06MHz. It is shown that the sonochemical yield produced by the bifrequency irradiation appears to be much more than the sum of yields produced separately by the two irradiations. This result has provided a heartening prospect for the development of sonochemical technology.