Piezoresistive effect is an important property of conductive polymer composites (CPCs), but it is still unclear that the conductive behavior of the composite under dynamic loading.To characterize such a system, we studied the variation in electrical conductivity of a conductive polymer composite under shock waves.The polymer matrix is polyamide-6 with carbon nanotubes and stainless steel fibers are the fillers.The detection systems measured resistivity in microsecond regime.The experimental analyses indicate that the resistivity decreases initially by 78.9％ under the loading shock wave, but sharply increases by 3358％ due to the unloading shock wave.Scanning electron microscopy (SEM) reveals that this resistivity increase is due to damage by the unloading wave and subsequent failure of many micro-conductive channels in the material.