New types of piezoelectric damping materials, piezoelectric ceramic (PZT) powder/carbon black (CB) powder/epoxy (EP) resin composites, were developed, and their mechanical and damping properties were studied. Here the mechanical energy of vibrations and noises were transformed into electric energy (current) by PZT, and the electric current was conducted to an external circuit through CB powders and then dissipated as thermal energy through a resistor. When CB was added to PZT/EP (70/30 in wt%), the mechanical loss factor (η), a measure of mechanical of damping intensity, showed a maximum value of ∼0.08 at the CB content of ∼0.51 wt%, at which the CB particles electrically just contact each other. In the present work, it was found that the PZT/CB/EP composite of 90.0/0.5/9.5 shows a large η value of ∼0.15.