Abstract: An oscillometric method for determining hemodynamic parameters of the arterial portion of patient's circulatory system, consisting in recording the pulse pressure waves in the major arterial vessel under examination, under the effect of a linearly varying pressure in a pneumatic vessel-constricting pressure cuff, with the result that a closed contour is formed within a single measuring cycle, which is established by straight lines the points of intersection of which are the signs of arterial pressure, while the amplitude values of the pulse waves in the contour determine the geometric parameters of the major arterial vessel under examination. A measuring system for carrying the method into effect features a linear characteristic of conversion and a straight horizontal amplitude-frequency characteristic in a frequency range of approximately from 0 to 50 Hz along a through path of conversion, amplification, and recording.