Abstract: Under combined irradiations of laser and ultrasound,cavitary bubbles are generated on the surface of gold nanoparticle.The laser-induced thermal effect,ultrasonic cavitation effect and the synergistic effect of laser and ultrasound are studied by means of the investigation of the dynamical process for the vibration of the cavitation bubble, with different external conditions such as laser power,ultrasound intensity,etc.It is found that dynamical process of the cavitation bubble can be modified by the irradiation of laser or ultrasound.The enhancement of laser power can increase the critical radius of the cavitation bubble,while that of ultrasound may intensify the vibration.Cavitation bubble may become more stable due to the synergistic effect of laser and ultrasound.It is also found that variation of the coupling between laser and ultrasound can affect synergistic effect.