The measuring time permitted for a pressure bar transducer is usually limited by the length of the pressure bar itself. To overcome this, we have studied the dyna-mic transmitting behavior of the pressure bar. Our results show that to obtain the correct pressure profile, one must reduce both the radial vibration in the neigh-borhod of the top end of the pressure bar, and the interference of reflected waves from the lower end with the incident wave. This paper presents a design for a pres-sure bar based on the principle of wave velocity dispersion, by which the perfor-mance of the transducer is greatly improved. The chief merit of the present design is that the permitted measuring time is no Longer limited by the length of the pres-sure bar.