Abstract: Organic montmorillonite (OMMT) /epoxy resin was used to modify asphalt via melt blending，and the compatibility of the compatibilizer and asphalt，as well as the microstructure，tensile strength，break elongation，thermal stability and viscosity-temperature properties of the modified asphalt，was characterized by means of FT-IＲ，XRD，fluorescent microscopy，universal material testing，TG analysis and Brookfield viscometry． The results show that (1) the dispersion of epoxy resin in the modified asphalt becomes more uniform due to the incorporation of OMMT，which results in an exfoliated structure; (2) the high-temperature performance and mechanical properties of the modified asphalt improve after the doping of OMMT; (3) as compared with the asphalt modified with epoxy resin，the asphalt modified with OMMT/epoxy resin exhibits better thermal stability，with increase of 30． 1℃ and 15℃ in initial and final decomposition temperature respctively; and (4) the asphalt modified with OMMT/epoxy resin is suitable for road construction due to its gently improved viscosity during the curing process．

Key words: organic montmorillonite, epoxy resin, modified asphalt, mechanical properties, thermal stability