In the present study we have prepared the different blend samples of cardanol-based epoxidized novolac resin (ECF) containing varying concentrations of CTBN ranging between 0 and 25 wt % with an interval of 5 wt %. The ECF was synthesized from the epoxidation of CF with molar excess of epichlorohydrin. The CF resin was synthesized with a different molar ratio of CF using dicarboxylic and tricarboxylic acids as a catalyst. The formation of various products during the synthesis of CF, ECF, and blending of ECF with CTBN has been studied by FTIR spectroscopic analysis. Further, a reaction mechanism for the step-growth reaction was proposed on the basis of the results of FTIR analysis. Also, the structures of CF and ECF were proposed on the basis of the results of NMR and MALDITOF mass spectroscopic along with GPC analysis. The DSC scans showed the cure temperature of epoxies and their blend samples with CTBN. Thermal stability of the blend sample containing 15 wt % CTBN into the pure epoxy resin was the highest among all other prepared systems. The blend morphology, studied by scanning electron microscope, showed the presence of two-phase morphological features.