Abstract: Based on Laser Reflective Tomography(LRT),the measurement method in near fields of ultrasonic transducers was investigated.The principle of LRT in measuring the distribution of ultrasonic fields was introduced and an experiment system was set up.Acoustic pressure of a multiple element piston transducer was measured using a laser vibrometer,and its distribution in amplitude and phase was obtained.The acoustic pressure in the same region was measured using a needle hydrophone,so the results from the LRT method were validated.Furthermore,through the reconstruction of acoustic fields,it indicated that LRT method was suitable for predicting distribution on transducers' surface and conditions of active elements.