Traces of paleoearthquakes have been found at many archeological sites in Japan. However, most of them have been neglected to date and not considered to be a subject relevant to archeological research. The author has studied these traces since 1988, naming this new study field "Earthquake Archaeology". The field has become popular both in archeology and paleoseismology and many important and useful results have been gradually obtained. These developments will lead to a deeper understanding of the natural and cultural history of the earthquake-prone country, Japan. Most paleoearthquake phenomena present at archeological sites manifest as liquefaction, lateral spreading and landslides. Detailed geological observations may also contribute to a reduction in damage caused by big earthquakes.