Chatter vibration is one of the important issues, as it deteriorates surface roughness of the workpiece and shortens tool life . Especially in boring, a tool has cantilever shape, which is flexible enough to vibrate. Piezoelectric actuators are small and can provide large force. They extend their applications in vibration control. One of practical control methods uses the dynamic interaction between mechanical and electrical LR circuits. A LR circuit plays the role of a dynamic damper, where passive vibration control theory can be applied. Yamada proposed a method to amplify control forces by using an acceleration amplifier, which has several advantages compared with the conventional active control method. In this paper, we applied this dynamic damper design for the chatter suppression of a boring bar equipped with piezoelectric actuators.