Abstract: A vibration damper with a hydraulic damping mechanism for vehicle spring systems, in which damping valves operating by throttling the pressure medium displaced out of one working space into the other working space are interconnected between two working spaces of the hydraulic pressure medium; the two working spaces are short circuited by a by-pass connection by-passing the damping valves whereby a by-pass valve is also interconnected into the by-pass connection which operates as a function of oscillation velocity and whose valve adjusting member adjusts the by-pass connection to a narrower cross section with rising oscillation velocities.