Nano composites of fumed silica/EPDM have been prepared by the convenient technique, using an open mill mixer. The obtained vulcanized fumed silica/EPDM composites have been subjected to FTIR investigation to confirm the molecular structure in the composites matrix. The dc conductivity  investigation  was carried out for fumed silica/EPDM nano composites  from room temperature up to 453 °K . The results illustrate a thermal activation  with  activation energy  in the range 0.026 and 0.036 ev. The values of conductivity at room temperature don't show remarkable variation with fumed silica.    The stress-strain of fumed silica/EPDM nanocomposites was studied at room temperature for different concentrations of fumed silica 5 -25 phr. In addition, the tensile study for silica /EPDM illustrates yield transition for the different silica concentrations. A significant values of  modulus ;  resilience ; stress and strain at fracture  are  discussed on the basis of silica particle  - silica particle ; silica - EPDM  cohesions as well as  composite  matrix free volume .