Abstract: By a meticulous study of INDEPTH deep seismic reflection profiles,the authors found that not only the strong reflection line-ups of the deep seismic reflection profiles may reflect the structure of the deep interior of the crust but also the seismic phases in the upper,middle and lower crust have somewhat different features.By applying the seismic phase analysis in the study of deep seismic reflection exploration,we may use the difference in seismic phase features to interpret the deep reflection seismic profiles sufficiently,and thus more abundant and reliable materials may be provided for the study of the crustal structure.