Abstract: An automatic stabilizer for the high-speed drill spindle in which when the rotation speed of the drill spindle is in excess of the natural frequency, the vibration centric momentum goes in the opposite direction of the mass imbalance. While the rotation speed is much higher than the natural frequency, the phase difference between the vibration centric momentum and the mass imbalance. A this instance, the rolling elements are inclined to move to the large radius side, in other word moving in the direction opposite to the mass imbalance so as to offset it to achieve the automatic stability in the drill spindle.