In Tsushima Island, characteristic wooden Folk houses are distributed. They are constructed with pillars shaped rectangle section. The detail of the structure is investigated on this report. As a result it was realized that componentry of Daidokoro is different from other rooms. Design characteristics are changed by placement and the size of the Hirabashira. Structurally, Hirabashira is used as a bearing wall. And the building becomes strong because of big timbers are put together rigidly.
