The Dong ethnic minority is one of the 55 ethnic minorities in China, and inhabits in the southwestern area of China. Their skillful technique of wooden architecture such as drum towers and timber covered bridges called "wind and rain bridge" is well-known. The Chengyang bridge in the Sanjiang autonomous county of the Dong is famous for the best work of unique timber covered bridge they constructed. The bridge is 64.4 meters long with four spans, and has roof with tiles and five pagodas with multi-tier pavilions located symmetrically on the superstructure. The bridge is splendid structure and harmonizes with surrounding environment. In this paper, structural characteristics of bridge girders and bridge piers, and necessity of roof and pagodas on the Chengyang bridge the author visited before are described. Besides, the structural characteristics of the other timber covered bridges the Dong ethnic minority constructed are reported.