In this paper, a three-phase composite with electrically conductive carbon black (ECCB) and piezoelectric ceramic particles, PMN, embedded into butyl (PMN/ECCB/IIR) was prepared by simple blend and mold-press process. Dynamic mechanical properties with various ECCB loading were tested by dynamic mechanical analysis (DMA). DMA shows that the ECCB loading has remarkable effect on the dynamic mechanical properties of the three-phase composite. The temperature range of loss factor (tanδ) above 0.3 the composite was broadened by almost 100°C and the maximum of loss factor shifts to higher temperature in the testing temperature range respectively with increasing the ECCB loading. The piezoelectric damping theory was used to explain the experimental results. The three-phase composites with proper composition can be used as high damping polymer materials.