Abstract: During the propagating processes of the level and uniform velocity landslide bore,a shock wave is formed when the landslide object is advancing at the uniform velocity.When it stops advancing,a rarefaction is formed between the landslide object and the shock wave Then the interaction will occur when the raretact ion cat ches up with the shock wave.The article provides a quantitative research on the reflection shock wave and the incidence shock wave generatd by the interaction.Based on the track equations of the incidence shock wave,some quantitative relations between wave heights,wave speeds and others concerned are obtained,and some simple computing methods are presented to solve them.