Styrene-butadiene-styrene(SBS)modified bitumen crack filling material with or-ganophilic montmorillonite(OCFM)was prepared by melt blending.X-ray diffraction analysis shows that the interlayer spacing of organophilic montmorillonite(OMMT)in OCFM is widened and an exfoliated structure may be formed.Thermal-oxidative aging behavior of OCFM and SBS modified bitumen crack filling material(SCFM)was investigated.The experimental results indicate that the rate of thermal-oxidative aging of OCFM is much slower than that of SCFM,which can be attributed to barrier of exfoliated structure of OCFM to oxygen.