A new epoxy resin containing both naphthalene and dicyclopentadiene (DCPD) groups was synthesized to produce a highly heat-resistant network, and the curing behavior was investigated using diaminodiphenylsulfone (DDS) as curing agent. The chemical structures were characterized with FTIR spectroscopy, NMR, MS, and GPC analyses. Dynamic curing behavior was investigated using differential scanning calorimetry (DSC). The physical properties of the resulting polymers were evaluated with dynamic thermal mechanical analyses (DMTA) and thermogravimetric analyses (TGA). The cured polymer showed great improvement in heat-resistant property including remarkably higher glass transition temperature (T-g) and thermal stability. Such properties make this new epoxy resin highly promising for heat-resistant applications. (c) 2006 Elsevier Ltd. All rights reserved.