Epoxy resins are polyether resins containing more than one epoxy group capable of being converted into the thermoset form. These resins, on curing, do not create volatile products in spite of the presence of a volatile solvent. This book overviews the structures of epoxy resins. New developments in flame-retardant, epoxy monomers and curing agents are described. It is shown that the main attention in recent years has been focused on phosphorus-containing epoxy monomers and epoxy resins.