The 1999 Chi-Chi earthquake induced a large scale of plane failure at the north bank of the Ching-Shoei River at Tsao-Lin area. Then, a new colluvium dam with 5 km length and 50 m height was formed on the Ching-Shoei River. Due to the instability of the nature dam, the water conservancy Agency, Taiwan plans to evaluate the potential of seismic hazard and slope instability in the Tsao-Lin area. This project aims to perform the seismic hazard analysis and rate the degree of slope failure potential. The proposed works include geological mapping, air photo interpretation, and seismic refraction/reflection explorations. The exploration results will be adopted for performing the seismic hazard analysis and rating the degree of slope failure potential.