The electrical properties of carbon nanotubes (CNT) elastomeric composites make them good candidates in a variety of applications, for example strain sensing and damage localization. In this work, static and dynamic piezoresistive behaviours of composites made of EPDM matrix, reinforced by a mix of carbon black (CB) and CNT were studied. The weight fraction (wt. %) of CNT was ranging from 0 to 5 %.The change of resistance during quasi-static tests is attributed to the reorientation and sliding of the CNT following the movement of the elastomer macromolecules. Samples with less CNT have a higher sensitivity. Dynamic tests were done using a split Hopkinson pressure bars apparatus (SHPB). An increase of the resistance is observed during dynamic compression. After dynamic compression, the resistance was thirty times higher and the stiffness 75 % lower. Scanning Electron Microscopy revealed that micro-cracks propagated in the direction of the impact loading inside the matrix.