Kasho Dam is a 46 meter high concrete gravity dam located in Tottori Prefecture in western Japan. On October 6, 2000, an earthquake of JMA—Japan Meteorological Agency—magnitude 7.3 (moment magnitude 6.6) occurred in the western part of Tottori Prefecture. According to the JMA, the source fault was thrust type in the EW direction of compression which is typical of this region. Kasho dam was built in 1988 for flood control and municipal water supply purposes. The dam has nine ungated crest spillways and one gated outlet in its middle elevation. Measured PGA was 0.5g and 2.0g at the foundation gallery and dam crest respectively. The dam sustained no damage except minor cracking of a concrete cantilever beam for the service gate hoist on the crest. 3-D reproduction analyses were performed of the crest structure and transverse joints, and the effects of modeling of crest structures, foundations and transverse joints on the numerical analysis results were examined.