Abstract
The castle of Nagahara was built in the late 16c. by Ieyasu-Tokugawa, and was enlarged in the 1634 by a grandson of Ieyasu for the camp. On this castle, we cleare the origin and the late structure. Plan of its late castle are made up of the main, secondary and third quarters, and each quarters are separated by the dikes. Main building sits in the main quarter, and it is separated to three blocks (ceremonial, living and house holding). This arrangement shows a model plan of the mansion-house in the early Edo-period. In the secondaly quarter there exist the management-house. And in the third quarter we have something interest in the watch box. One of the its plans are similar to the present farmers' houses. But, these buildings have pulled down at 1685, and do not remain at present.
