A vibration damper for vehicle is composed of hydraulic cylinder piston in hydraulic damper, magnetizing ring assembly consisting of magnetic and non-magentic rings on the piston rod, magnetorheologic liquid in the clearance between the said assembly and the inner surface of cylinder, and a coil wound at central position of magnetic ring. When a current flows through the said coil, the magnetorheologic liquid is quickly quasi-solidifed under the action of magnetic field, making the damper have controllable damping force for optimal vibration damping effect.