Abstract: Investigation of the echogram of a liquid cylinder in homogeneous scattering medium is described. A model have been done and experiments on some sorts of liquid cylinder have been made. An expression is derived for the brightness function of the ech-ograms, which are based on the use of STC （Sensitivity Time Control）. According to. this expression, the experiments on some sorts of medium with different ultrasonic properties have been simulated by computer. These results enable us to estimate ultrasonic properties of a liquid cylinder by its echogram.