A ventricular assist system includes: a ventricular assist blood pump provided with a rotational part having an impeller and a housing which houses the rotational part therein an introduction-side artificial vessel which introduces a liquid into the ventricular assist blood pump and a delivery-side artificial vessel which delivers the liquid from the ventricular assist system. In the ventricular assist system, a difference between a maximum flow rate and a minimum flow rate of a liquid in a state where the ventricular assist system is connected to a liquid-discharge source which discharges the liquid while increasing and decreasing the flow rate of the liquid at a fixed cycle is 40% or more of a difference between the maximum flow rate and the minimum flow rate of the liquid in a state where the ventricular assist system is not connected to the liquid-discharge source.
