The Kiragawa-cho in Muroto city, Kochi prefecture, which will be the most heavily damaged area in the next Nankai earthquake, is selected to consider how to reduce the earthquake damage of traditional wooden houses in the important district of groups of historic buildings. A questionnaire survey for local residents and evaluation of seismic capacity and durability for existing houses are performed. As results, the following conclusions are obtained. 1) Some houses have poor seismic performance. 2) It is possible to identify vulnerable houses by microtremor measurements. 3) Long term measures accordance with a whole life design of residents is necessary for houses in this districts.
