In order to clear the transition of design style, we have studied on the Duoi Keo design of wooden architectures in The Nguen Dynasty at Hue. The conclusion of this paper is as follows. : 1. To clarify the production age of the Duoi Keo design of wooden architectures, we have cleared the creation age and detailed repair of 34 wooden architectures in existence by the document and hearing. 2. We have classified the Duoi Keo design of wooden architectures to four types, A type is “両渦文型”, B type is “龍頭吐水唐草文型”, C type is “小龍頭渦唐草文型“, D type is “渦唐草文型”. 3. The transition of the Duoi Keo design is as follows. A-type →B-type →C-type and D-type. 4. We have presumed the new construction age of the wooden architectures in existence, that is that Dien Tho Ninh was built in 1820, the upstairs of Ngo Mon was built in 1921-23, and Hung Mieu was built in the middle of 19 century.
