Nowadays, conductive polymer composites have many applications such as electronic components, polymer anodes, cable coverage and etc. Compared to metals, conductive rubber composites have some advantages such as low density, ease of shaping, flexibility, wide range of electrical conductivity and corrosion resistance. These composites have special applications like flexible solar cell, biosensors, polymer anodes and etc. conductive carbon black and metallic particles are commonly used as Conductive fillers. Various rubbers such as NR, NBR, EPDM and silicone rubber are used for conductive composites. Among rubbers, NR has been atteracted a lot of attention due to good processability, low prices, availability, and highest elastic properties.However, iite of its high electrical resistance, there are some applications that repair electrical conductivity of NR. In this study, copper nanoparticles have been used as conductive fillers to increase the conductivity in natural rubber. In order to increase the compability between Copper particle and natural rubber,nanoparticles surfaces were modified with stearic acid and then applied into natural rubber .Incorporation of Copper particles into natural rubber was carried out in two ways, melt mixing and solvent/melt mixing method. Vulcanisation of the compounded NR was carried out under the same conditions. The samples containing various amount of nanoparticles were cured with two different curing systems (conventional and efficient). Electrical resistance of the prepared samples was measured using a four- electrode method. Threshold percolation and microstructure of samples were analyzed using scanning electron microscopy. Mechanical properties, crosslinking density and ozone resistance of specimens respectively were measured by tensometer, swelling and ozone resistance tests according to ASTM standard method. The results of this study show that the addition 0.5 phr copper nanoparticles there is no significant change in the electrical conductivity. The higher value of copper nanoparticles in natural rubber increases the electrical conductivity. In 1 phr copper nanoparticles the threshold percolation occurs and electrical conductivity reaches its highest value. But always, The electrical conductivity increasing with increasing the copper particles amount will not happen simultaneously. Between copper particles and sulfur always a chemical reaction happens at curing temperatures Which leads to the production of copper sulfide. In addition, the formation of copper sulfide particles have results in electrical conductivity reduction compared to original copper particles in other hand By taking out the sulfur affect negatively on crosslinking density of polymer networks and reduce the number of crosslinking per unit volume .also Reducing the amount of crosslinking density, electrical conductivity also drops. This process normally occurs in both sulfur curing systems, efficient and conventional vulcanization. Microscopic images of samples were taken for different percentages and was determined by the method of solvent - melt separation is more desirable to achieve maximum dispersion and distribution. Similarly, samples with different percentages of the composition of the particles were chosen to test the elasticity and hardness measurement. Samples of their electrical properties were favorable for ozone resistance test were selected. The results of these tests showed that the presence of copper nanoparticles in natural rubber as a barrier against the penetration and growth of cracks caused by the ozone destruction. Ozonide sample were taken from the ATR-IR test. The results show that the reaction between ozone and unsaturated bonds of polymer chain lead to degradation and carbonyl groups in the molecular structure emerges . The samples with high electrical conductivity test was used to determine the conductive heat transfer coefficient on the lead . The test results show that the presence of copper particles increase the thermal conductivity of the composites. Keywords: aturalRubber,Copperanoparticles,ElectricalResistivity,OzoneResistance.