Generally speaking, deep seated landslide is caused by the fast rising of groundwater level. For the understand of the relationship between groundwater level and deep seated landslide, this study adopted the medium size of dammed lake in Chiufenerhshan as the sand of laboratory experiment to set up several slopes in the sand box. The seepage flow was forced into the slope by lateral/upward direction, so as to rise the groundwater level. The groundwater level fluctuation was recorded during the period of deep seated landslide. The instant recording of soil movement during the experiment was also executed. Finally, the cause and the mechanism of deep seated landslide was discussed based on the physical model. In other words, the outcome of this study can be the basis of physical model.