The electrical and dynamic mechanical behavior of barium titanate (BaTiO3)/vapor-grown carbon fiber (VGCF)/Low Density Polyethylene (LDPE) composites has been studied. The measurement of electrical conductivity exhibits a lower percolation threshold and a more distinct two-stage percolation region, especially with a wide plateau between the two stages, for BaTiO3/VGCF/LDPE composites compared to the two-component system of VGCF/LDPE. This can be attributed to increase of the effective concentration of VGCF and the obstruction of BaTiO3 particles on VGCF networks. The dynamic mechanical spectra of BaTiO3 /VGCF/LDPE composites present a distinctive ct relaxation region with its peak value nearly remaining constant at its high temperature side in contrast to the abrupt decrease of LDPE. Moreover, the loss factor in the alpha relaxation region reaches its largest value for the composite of 8 vol% VGCF content. This means that the piezo-damping effect really functions in BaTiO3/VGCF/LDPE composites and only in certain conditions can this effect have practical significance. Further examination of the damping behavior in a different relaxation region demonstrates that the piezo-damping effect is directly related to the relaxation behavior of the polymeric matrix. Also, the piezo-damping effect is highly temperature and frequency dependent. The dielectric measurements suggest that, before the formation of a certain critical conducting state, the energy dissipation approach of the piezo-damping effect may be mainly determined by the interfacial polarization effect in the composite. Thus, it may be inferred that the piezo-damping effect also contributes to the dramatic increase of the loss factor at the high temperature side of the ct relaxation peak for the BaTiO3/LDPE composite and functions practically even if there is no presence of VGCF.