A vibration damping system for an elevator is provided with a damping device (5) that is provided between a cab (1) and a car frame (2) for supporting the cab (1) and whose damping coefficient can be changed. A speed detector detects the traveling speed of a reference elevator car, and a calculation unit (15) receiving the traveling speed detected by the speed detector calculates a control signal for the damping device (5), and outputs the control signal to the damping device. The calculation unit (15) controls the damping device (5) in such a way that, in the case where the traveling speed exceeds a predetermined value, the damping coefficient of the damping device (5) is larger than that in the case where the traveling speed is the same as or smaller than the predetermined value.