Metal powder (Cu) filled Epoxy resin (EP)/Organic-montmorillonite nanocomposites were prepared, where the compounding was carried out by using hardener with filler loadings of 0wt%, 5wt%, 10wt%, 15wt% and 20wt%. Organic-montmorillonite was prepared by using the method of Secondary-intercalating with transition metal ion and cetyl trimethyl ammonium bromide (CTAB) as the modifier. The content of Organic-montmorillonite dispersed in EP system was 3wt%.The effect of filler loadings and incorporation of coupling agent on tensile properties and thermal conductivity are studied. The results demonstrate that, an increase in filler loading is found to increase the tensile strength and thermal conductivity of M filled EP composites. By adding 2% coupling agent, the decrease of tensile strength with increasing filler loadings can be observed in 20%Cu-EP composite. However, the addition of 2% coupling agent in 20%Cu/OMMT/EP composite allowed the increment of tensile strength and assisted in greater increment of thermal conductivity of the composites.