Abstract:Starting from the basic principle of seismic wave formation, the paper discussed the physical meaning of seismic data and relationship with geologic information. The seismic section is not geologic section, it should build up the relationship between the seismic data and geologic information if making geologic interpretation of seismic section. On that basis, I analyzed the currently popular horizontal slice technique and pointed out its adaptive range and existed problems. Using horizontal slice to study structural and special rock body features is effective, which more approaches to isochronal surface geologically than general time slice. But if mistaking the sample values of seismic records for amplitude values and using slice data in small time window even at a sample point to study the relative stratigraphic lithology and further to study the variation of lithology and sedimentary development, which violates the basic relationship between the seismic and geologic data.