A new Schlieren method for visualizing an acoustic field of pulsed ultrasound wasproposed, and a system was developed to evaluate the validity of the proposed method byvisualizing an acoustic field of a focused ultrasound field of diagnostic frequency range. Aconventional Schlieren optical system is not used in the developed system. The system uses ashort-pulsed laser, a CCD camera with a wide dynamic range, and a PC that processes imagescaptured by the CCD camera. In the proposed method, extraction of light diffracted byultrasound is carried out by subtraction of images captured with and without ultrasoundexposure. The usefulness of the developed system was confirmed by an experiment in whichacoustic fields of a 5 MHz focused transducer were visualized. Good agreement was foundbetween the visualized and simulated ultrasound fields.