The stilbene epoxy resin having two different aryl groups of the following formula:
wherein R 1 through R 8 independently represent acyclic or cyclic alkyl groups having 1 through 6 carbon atoms, hydrogen atom or halogen atoms, and the epoxy resin mixture including such stilbene epoxy resin according to the present invention have lower melting points than those of the stilbene epoxy resin having two identical aryl groups and the epoxy resin mixture including such stilbene epoxy resin. Compared with the conventional resins, the resin or resin mixture of the present invention accordingly has improved working and molding properties, thereby shortening the time required for the molding and working process and giving economical advantages and preferable productivity. The epoxy resin or resin mixture according to the present invention is preferably used as adhesive, coating, or insulating material, as electrical or electronic material for laminated sheets or the like, and especially as material for encapsulating electronic parts.