The peel strength of silica filled on two grades of epoxidized natural rubber (ENR), i.e., ENR 25 and ENR 50 adhesive were investigated using coumarone-indene as the tackifying resin. Toluene was used as the solvent throughout the study. Result shows that peel strength increases with increase in silica loading due to the concentration effect of the filler. Peel strength, however, shows maximum value at 40 phr silica for both ENR 25 and ENR 50 an observation that is attributed to the maximum wettability and compatibility of adhesive on the substrate.