Abstract:The motusi buildings in Xincheng, Guangxi province, were built in 1582, the tenth year of the Wanli reign period of Ming. As one of the best preserved of their kind located at the outskirts of Chinese culture, they were listed as a National Priority Protected Site in 1996. The motusi buildings belong to the highly formalized system of government-sponsored architecture, but the usage of certain building methods reveals the influence of regional and local building traditions. The reconstruction of the original construction ruler (yingzaochi) indicates: the length of each building was different and increased gradually from 30.8cm to 31.8cm; the central bay was designed using a base unit of 15 chi (feet); the length, width, and height of interior space was adjusted by adding or subtracting the dimensions of the base unit; the complex was laid out on a grid of 15 chi but the yashu cluster on a grid of 5 chi (corresponding to 1 bu or pace); the main building was situated in the geometric center of the complex. A comparative analysis demonstrates similarities between these tusi buildings and the design methods used for official-style and/or Cantonese architecture. Therefore, this case study serves to the explore the rules and origins of Chinese regional architecture.