Closed cell rubber foams, based on natural rubber (NR)/ epoxidized natural rubber (ENR)/ nanoclay nanocomposite, were produced by using Azodicarbonamide (ADC) as chemical blowing agent. Effect of temperature, foam density and formulation parameters such as ENR type and content, carbon black content, nanoclay type and content and ADC content on curing behavior, morphology (cell size and cell distribution), mechanical properties as(compression behavior, resilience and hardness), absorption and reflection behavior of sound waves were examined. A novel one-step compression molding was proposed and successfully employed for preparation of the foams. The uniqueness of this new method was that both the foam density and expansion ratio became independent of the CB, nanoclay and ADC content. Results showed that increase in the CB content from 0 to 20 phr yielded a 0.91 and 3.51 Nm increase in the initial and the final torque, respectively. The SEM results demonstrated that the prepared foam had three different layers including the skin, transition and core layers. Almost fourteen-fold enhancement of the cell density (from 8 to 117 cells/cm 3 ) was obtained by increasing the CB content in a constant foam density. Although, curing properties, cell morphology and mechanical properties of the foam improved by increasing the CB content, the gradual deterioration was observed for sound absorption properties. The effects of three different nanoclays were examined. XRD and TEM results showed that the Cloisite Na + agglomerated in the matrix while an intercalated-exfoliated/exfoliated morphology was seen in the Cloisite 30B and the Cloisite 20A, respectively. The rheometer results showed that the organo-modified nanoclays, which were the ammonium-salt modified nanoclays (Cloisite30B and Cloisite 20A), improved the foams’ curing behavior more than the pristine Cloisite NA + . Meanwhile, the SEM results showed that the nanoclay increased the cell density and decreased the cell size, depending on the nanoclay type. The mechanical properties of NR nanocomposite foams including the hardness and the modulus were improved by incorporating the nanoclays. The increase in the ADC content from 1 to 10 phr yielded in a 94%, 55% and 70% increase of the Hardness, Elastic modulus and resilience, respectively. The gas pressure inside the bubbles increased by increasing ADC content. The simultaneously improvement in the modulus and hardness with resilience in rubber materials is reported for first time. The rheometer results indicated that ADC acted as inhibitor of curing process and decreased as 75%, 32% and 17% of the curing rate, the initial and the final torque, respectively. The scanning electron microscopy results demonstrated that all the foams had uniform structure and the maximum and minimum cell size (550 and 330 µm) was occurred in the sample with 3 phr and 10 phr of ADC respectively. Keywords : Rubber foam, Azodicarbonamide, Natural Rubber, Epoxidized Natural Rubber