In this study, a new kind of damping composite consisting of chlorobutyl rubber, poly(ethyl acrylate), piezoelectric ceramic (PZT), and carbon black (CB) was prepared, and some efforts were made to characterize the damping behavior and explore the damping mechanism. The damping behaviors of the composites were mainly decided by the contents of CB and PZT. When an external vibration was exerted on the composites, the mechanical energy of vibration was transformed into electric energy by PZT; if the resistance was adjusted to a suitable range by the variation of the CB content, the composites could behave as semiconductors: the electric energy could not be transferred to the surface of the material but rather was dissipated as thermal energy. For this system, when the contents of CB and PZT were between 10 and 30 vol %, respectively, the volume resistivity was between 10(5) and 10(9.5) Omega cm, and a good damping performance could be achieved. On the basis of the results, a theoretical model is proposed to explain the damping performance of the composites. (C) 2008 Wiley Periodicals, Inc.