Abstract: In order to perform photoacoustic imaging with highcontrast and fast speed, we studied the influence on the reconstructed images of the number of detection positions by a singleelement transducer circularly scanning targets. A Qswitched Nd: YAG laser, operating at 1 064 nm, was used as the illuminating source. The laser has a 7 ns pulse width and a repetition frequency of 20 Hz. A needle polyvinylidene fluoride(PVDF) hydrophone with 1 mm diameter was used to detect photoacoustic signals. We reconstructed the photoacoustic images of 26 letters, 12 hairs, leaf skeleton and simulated blood vessels. Both simulation and experimental results show that an optimized strategy in both imaging quality and speed can be achieved by evenly detecting 100 times around the circle, and the image reconstruction time is 5.903 s. The results of this study would help the performance and design for both scanning singleelement transducer and ring array systems.