Nukisaki-jinja, which has been the highest shinto shrine of Kozuke province (now Gumma prefecture), has a history of its unique architecture. The official record written on the backside of the Engishiki law-scroll inherited by the Kujo clan tells us about its main shrine and the temporary shrine for the god-moving (Sengu), both built in 1025 A.D. The most important members of their structures were the ridge-supporting-posts (Muna-bashira) and the eaves-supporting-posts (Nokibashira). Building construction with the ridge-supporting-post, generally speaking, has been rarely used after the introduction of Chinese architecture and, at present, only its pretended vestiges are seen in the main shrines of Isejingu, the Great shrine of Izumo and other few shrines. But four ridge-supporting-posts in the main shrine (three in the temporary shrine) of Nukisaki-jinja all supported the ridge actually. The fact would be a very important information about Japanese native architectural technique. On the other hand, the existing main shrine of Nukisaki-jinja, rebuilt in 1635 A.D., has an appearance of a usual modern shinto shrine. But its dimensions are nearly equal to those of the former shrines above mentioned, and an inside ridge-supporting-post, called Shin-no-mihashira, still stands in its former position. And the sanctuary is on the upper floor, while usual shrines have no upper floor. These features of the existing shrine reveal the original form of the shrines of Nukisaki-jinja, which have probably had preserved the form of the primitive dwelling house of ancient Japan.