Tight as a thread, seamless as a seal, and coupled like yin and yang. For centuries,sunmao structures have been providing sturdy and durable supports for Chinese wooden architecture.

Large components of traditional Chinese wooden architecture, including columns, beams, purlins and dougong (interlocking brackets), are often pieced together using sunmao structures. The convex sun (tenon joint) and the concave mao (mortise), when interlocked, both support and contain the adjoining parts. This augments stability, but also adds flexibility to the architecture, strong enough to resist earthquakes. Craftsmen can make and process the components in advance and assemble them quickly on site, which is simple and efficient

The Hemudu site in Yuyao, East China's Zhejiang province, dates back around 7,000 years.Hundreds of wooden components with sunmao structures have been unearthed from the remains of stilted houses there, the earliest known application of sunmaostructuresin China in wooden-frame buildings.

Since the Shang (c. 16th century-11th century BC) and Zhou (c. 11th century-256 BC) dynasties, generations of carpenters, with their ingeniousness, have produced more than a hundred types of sunmao structures. From such, a whole set of systematic methods was devised, from selecting locations and choosing materials, to structure, measurements, manufacture and assembly.

For the craftsmen who have preserved and guarded this heritage, and for the generations of people who have lived in and among the spaces defined by it across China, wood and wooden structureshave always been an important constituent of Chinese architecture.

Their styles may differ, but they all share the same root. Chinese people's love of nature and pursuit of harmonious coexistence is also embedded within.