Abstract: Hydroxyalkyal lignin was synthesized from alkali lignin with propylene oxide. Then it was epoxided by epichlorohydrin catalyzed via boron trifluoride etherate to form ligninbased epoxy resin. Using lignin-based epoxy resin and organic-montmorillonite (OMMT), lignin-based composite was prepared by intercalated polymerization. The compatibility of lignin- based epoxy resin and OMMT was excellent. When T31 and methyl hexahydro-phthalic anhydride were used as a curing agent, the tensile strength and impact strength of ligninbased epoxy resin/OMMT composite were stronger than lignin-based epoxy resin without OMMT. Thimbleful OMMT could increase the toughness and intensity of the lignin-based epoxy resin.