Ultrasonic Heating (1MHz, 0.5~1.0 W/cm,2,)for 30 minutes before irradiation euhanced the effect of radiotherapy, the inhibition rate of the combined treatment on S 180 in mice is 99.5%, whereas, for radiation alone, it is 68.4% and ultrasonic heating alone 89.9%.,Radiation or ultrasonic heating alone had no curative effect on the tumor when compared to the combined treatment, as seen in day 30 observation on tumor regrawth.