<div class="htmlview paragraph">An exeperimental study on the atomization characteristics of an ultrasonic Atomizer utilizing pulse laser holographic system is presented in this paper.</div> <div class="htmlview paragraph">The spatial distribution of the ultrasonic frequency and the pressure amplitude behind the atomizer were measured. It was shown by experiment that the sonic wave from the outlet of the atomizer travels as a spherical wave.</div> <div class="htmlview paragraph">The effects of the air pressure within the ultrasonic atomizer on the ultrasonic frequency and the pressure amplitude were studied.</div> <div class="htmlview paragraph">The effects of air pressure and fuel flow rate on the spatial distribution of the droplets and the SMD mean diameters were obtained.</div> <div class="htmlview paragraph">On the basis of experimental results, the atomization mechanism of the ultrasonic atomizer is discussed.</div>