||Epoxy molding compounds are widely used as semiconductor packaging materials. Generally epoxy resin compounds contain halogen compounds as flame retardant. However, halogen compounds generate toxic substances such as dioxin derivatives that create environmental hazard. Recently Halogen-free self-extinguishing epoxy composites have been developed for epoxy molding compound (EMC) for semiconductor packaging materials. In this study, the epoxy resin composites were produced by blending the biphenylene moieties in the main chains of novolac type epoxy resin and hardener with stoichiometric reactioin ratio. DSC, PCFC, and LOI techniques were used to characterized the thermal properties and flame retardancy of the epoxy composites.