Natural rubber (NR) and epoxidized natural rubber (ENR) were chosen to study the composites and blends of polymers. The presence of epoxide group caused to improve the mechanical properties in terms of modulus and tensile strength. Furthermore, dielectric spectroscopy revealed that ENR showed conductivity process at low frequency and high temperature. Epoxidized natural rubber containing 50 mol% of epoxide group or ENR-50 exhibited the highest dielectric permittivity and electrical conductivity. Therefore, ENR-50 was then selected to prepare polymer composite filled with barium titanate (BT) and carbon black (CB) particles. The permittivity and conductivity of the composites increased with the volume content of the fillers. The BT/ENR-50 composites reached a high permittivity of 4 8 . 7 for addition of 50 vol% BT. Meanwhile, CB/ENR-50 composite reached percolation threshold at 6. 3 vol% of CB. The phase development and miscibility of poly(vinylidene fluoride) (PVDF)/epoxidixed natural rubber (ENR) blends were then investigated. It was also found that phase structure depended on epoxidation level and blend compositions. The blend exhibited a co-continuous phase morphology in the region of 40 to 60 wt% of ENR-50. Furthermore, the results from dynamic mechanical and dielectric analysis revealed that these blends present a partial miscibility. Finally, the composites based on binary blends of PVDF/ENR-50 containing BT were prepared. The study of the morphologies revealed that BT was dispersed in ENR-50 phase in the case of simple blend. However, the addition of BT after dynamic vulcanization induced localization of BT in PVDF phase and at interface. The highest increment of permittivity can be observed for the composite based on dynamically cured PVDF/ENR-50 (80/20) blend