An extensive study on dynamic mechanical thermal analysis has been carried out to investigate the effect of filler-filler and polymer-tiller interaction in cured ethylene-octene copolymer reinforced by unmodified and modified silica. The silica was treated with trimethylolpropane triacrylate (TMPTA) or triethoxyvinyl silane (TEVS), followed by electron beam irradiation at room temperature. Modification of the silica tiller. especially via silanization, significantly reduces filler-tiller networking, as evidenced from the strain sweep tests, and thus helps reduce the Payne effect, particularly at high filler loadings. The effect of modification is quantified with the help of a new mathematical model correlating the storage modulus and the volume fraction of the filler. The enhancement in the storage modulus at high temperatures and changes in the loss tangent at the glass transition temperature suggest definite improvement in the polymer-filler interaction in the case of these modified fillers. The results obtained from the master curves constructed based on the time-temperature-super-position principle further support the findings.