Landslide area at Chiufenershan, Nantou county, was surveyed by using geological boring and salt logging method in order to understand the characteristics of stratum and groundwater. Six locations were selected to carry on the geological boring investigation. Each boring well depth was 45 m to 60 m From the geological boring core sample, the main geological stratum was brown and gray sandstone, and the thin layer shale appears occasionally. Also, shear rupture zone appeared from 40 m to 50 m depth, which was consistent with the slope failure depth induced by Chichi earthquake. Besides, the background value of groundwater specific resistance of the six wells was inconsistent, which showed groundwater of the six wells was divided into definite and probable flowing type. Groundwater aquifer upper the water table was not detected by salt logging test in the condition of lower water table because of little rainfall occurred in research period. Also, the groundwater aquifer of six wells was unconfined. The shear rupture zone of stratum was the position of groundwater flowed out.