In this research glycidyl methacrylate (GMA) which is a di functional monomer was used to graft EPDM. The grafted EPDM (EPDM-g-GMA) was used to eliminate the use of antiozonant and overcome the problem of distribution and co–curing in NR/BR/EPDM blend. Also in the blend of NR/BR/ENR/EPDM-g-GMA epoxidized natural rubber(ENR) was used due to its inherent polarity in its epoxide rings which in turn can react with epoxy pendant group in EPDM-g-GMA from one end , and from other end which is non – polar to NR. Fourier transfer infrared(FTIR)and titration results confirms grafting of EPDM with 6% GMA. Blends of NR/BR/ENR/EPDM-g-GMA with different amount of GMA, i.e.(5,10,30phr )were prepared. Some mechanical properties of NR/Br/ENE/EPDM-g-GMA blend, NR/BR/ENR/EPDM blend , and NR/BR with (which is an antiozonant in side wall of tire) were determined and compared. Results obtained from NR/BR/ENR/EPDM-g-GMA shows a uniform distribution of ingredients (filler , curing agents) in blends containing GMA. Tensile properties, tearing strength and ozone resistance of blend containing GMA were significantly improved compared to blend with EPDM(without graft)and NR/BR containing 6PPD. Comparing the results, the blend containing 5phr EDM-g-GMA shows optimum properties in comparison with other blends containing 10 and 30phr GMA.. In compound GMA-5, GMA-10 after 100 hours under described test condition no crack observed. It is due to fact that presence of epoxy groups that react with ozone and produce ketone compounds. Ketone groups provide a good ozone resistance in samples related to Ref-0 flows at edges were observed. Staining at surface of sample Ref-1 were observed. Although in these sample flows from edge, developed to flows in the middle of sample, but sample did not tear after 100 hours the reason of lower ozone resistance. Compared to Ref-0, GMA-5, GMA-10 is lack of compatibilizer in compound. Compound GMA-30 after 18 hours exposure to ozone, cracked and after 90 hours teared. The reason is lower compatibility in compound and therefore phase separation occurred Tear strength of 460 KN/cm , tensile strength of 24.18 MPa and elongation at break of 442% were reported which is 46.5% , 13.7% and 4.8% improved properties compared to NR/BR containing 6PPD. Results clearly indicate increase of tear strength up to 10phr of EPDM-g-GMA. This is due to fact that EPDM has low tear strength and also may be due to poor distribution and lower cross link density The novelty of this research is the first time ENR were used in the blend of NR/BR/EPDM , with significant effect on co–curing of NR/BR which is fast curing with EPDM which is slow curing. Physico-mechanical properties of NR/BR/ENR/EPDM-g-GMA in comparison with NR/BR/ENR/EPDM, NR/BR superior. For the first time ENR was used in compound. ENR has properties that is related as engineering polymers. The obtained results are 36%, 5% better than it was reported by other researcher on tear resistance and tensile strength. The best results obtained with optimum level EPDM-g-GMA. Key words : Ozone resistance , NR/BR/ENR/EPDM-g-GMA , Tensile properties , Tear strength