ABSTRACT A form of roof support that transmits the force of the roof ridge through axial loading to its triangular components matured in China by the time of the Sui (581 AD–618 AD) and Tang (618 AD–907 AD) dynasties. The structure attracted the attention of pioneering scholar of traditional Chinese architecture Liang Sicheng (1901–1972) in part because the structure bore similarities to the Western roof supports that later developed in the direction of the modern truss, and represented a road not taken by Chinese traditional architecture. Liang referred to the structure as a chashou. However, in the years since Liang’s death, scholars have applied the term chashou to an ever-broader range of angular components found in the Chinese architectural repertoire. By examining structural properties rather than external triangular forms, a more precise classification is proposed. Clarifying the unique features of the chashou in the Sui-Tang, this essay illustrates how a structure that matured by the time of the Sui Dynasty and the Tang reflected the gradual replacement of diagonal beam (xieliang 斜梁) rafter supports by China’s characteristic column and tie (tailiang 抬梁) construction.