Ultrasonic tissue characterization has been an active research field since the ultrasound was applied in medicine. It focuses on the quantitative information on the reaction of ultrasound and tissue. It is different from ultrasound imaging, which mainly represents the reflectors in the body. A practical design of an acquisition system is introduced, that meets the requirements of ultrasonic tissue characterization, that is to acquire the ultrasound signal from the same area of interest at a certain depth for a certain period of time. The whole acquisition system is composed of a commercial ultrasonic imaging machine, a custom made control box and an IBM-PC which has a high speed A/D board with a DT-Connector, connected to a high speed DSP board in the same computer.