This study dealt with the Maxwell stress effect of waterborne polyurethane (WPU)/ conductive filler nanocomposite, which was a promising candidate for a material to be used in dielectric elastomer actuator electrode. Conductive nanocomposites were produced by using three types of conductive filler such as carbon black (CB), vapor grown carbon fiber (VGCF), and silver powder (Ag). Among them, conductive nanocomposite containing VGCF exhibited the lowest threshold concentration. And the blend of CB and VGCF (CB/VGCF) filler had a synergistic effect to electrical conductivity. Actuation test showed that CB/VGCF nanocomposite electrode had the largest displacement. Then it could be stated that the improvement of the displacement in CB/VGCF nanocomposite electrode was originated from the increase in relative dielectric constant. In addition, a unique feature of the hysteresis in the bending deformation was described. The feature is that the prior application of an electric field significantly improves the bending speed in the successive application.