Abstract: For further systematic study on a kind of cutting chatter suppression structure based on electrorheological fluid damper developed earlier which has been used in turning chatter suppression successfully, the authors made experimental and theoretical study of its static and dynamic properties. All the results show that this kind of electrorheological fluid damper structure can notably change such static and dynamic properties of the cutting tool bar as inherent frequency, damp performances and so on. When the added electric field increases from 0 kV/mm and 1.5 kV/mm to 2 kV/ mm, the static flexibility of the cutting tool bar decreases from about 0.5 μm/N and 0.3 μm/N to 0.2 μm/N respectively, its damp ratio decreases from 0.051 27 and 0.02882 to 0.021 63 respectively; and the encircled area of its loading curve and unloading curve increases while resonance peak value decreases. This kind of structure can efficiently control the vibration of machine tools .