Abstract: In order to research the influence of different bandwidths of transducer on photo-acoustic imaging resolution, finite element simulation experiments were carried out. An empirical formula was obtained between transducer bandwidth and photo-acoustic imaging resolution. Experimental results showed that the reconstructed image resolution of absorbers was unchanged in the order of millimeters when the cut-off frequency of transducer was greater than 2 MHz; however, it was contrary for the frequency less than 2 MHz. The results are helpful for the choice of transducer and the evaluation of image reconstruction.