Large bronze masks, sacred trees, and other objects excavated at Sanxingdui display the distinctive artistic and ritual traditions of the ancient Shu region.

The precise ways the objects were used remain under study. They show regional characteristics while also allowing comparison with material elsewhere to investigate ancient exchange.

Archaeological site

The Sanxingdui archaeological site is located about 4 kilometres (2.5 mi) northeast of Nanxing Township, Guanghan, Deyang, Sichuan Province. Archaeological digs at the site showed evidence of a walled city founded c. 1,600 BC. The trapezoidal city has an east wall 2,000 metres (6,600 ft), south wall 2,000 metres (6,600 ft), west wall 1,600 metres (5,200 ft) enclosing 3.6 square kilometres (1.4 sq mi), similar in scale to the inner city of the Zhengzhou Shang City.

The city was built on the banks of the Yazi River, and enclosed part of its tributary, Mamu River, within the city walls. The city walls were 40 metres (130 ft) at the base and 20 metres (66 ft) at the top, varying in height from 8–10 metres (26–33 ft). There was a smaller set of inner walls.

The walls were surrounded by canals 25–20 metres (82–66 ft) wide and 2–3 metres (6 ft 7 in – 9 ft 10 in) deep. These canals were used for irrigation, inland navigation, defense, and flood control. The city was divided into residential, industrial, and religious districts organized around a dominant central axis. It is along this axis that most of the pit burials have been found on four terraces. The structures were timber-framed adobe rectangular halls. The largest was a meeting hall about 200 m (2,200 sq ft).

Metallurgy

This ancient culture had a well-developed bronze casting industry that permitted the manufacture of many impressive articles, such as the world's oldest life-sized standing human statue (260 centimetres high, 180 kilograms (400 lb)), and a bronze tree with birds, flowers, and ornaments (396 centimetres ), which some have identified as renderings of the Fusang tree of Chinese mythology.

The most striking finds were dozens of large bronze masks and heads (at least six heads with gold foil masks originally attached) represented with angular human features, exaggerated almond-shaped eyes, some with protruding pupils, and large upper ears. Many Sanxingdui bronze faces had traces of paint smears: black on the disproportionately large eyes and eyebrows, and vermilion on the lips, nostrils, and ear holes.

According to the French sinologist Corinne Debaine-Francfort, these colours provide evidence for ritual practices that were very different from those of the Shang dynasty. Vermilion is interpreted "not be coloring but something ritually offered for the head to taste, smell, and hear (or something that gave it the power to breathe, hear, and speak)". Based upon the design of these heads, archaeologists believe they were mounted on wooden supports or totems, perhaps dressed in clothing.

Liu Yang concludes "masked ritual played a vital role in community life of the ancient Sanxingdui inhabitants", and he characterizes these bronze ritual masks as something that may have been worn by a shi "personator, impersonator; ceremonial representative of a dead relative".

Another scholar compares these "bulging-eyed, big-eared, bronze heads and masks" with "eye-idols" (effigies with large eyes and open mouths designed to induce hallucinations) in Julian Jaynes's bicameral mentality hypothesis; and proposes, "t is possible that southern Chinese personators wore these hypnotic bronze masks, recursively representing the spirit of a dead ancestor with a mask that represents a face disguised by a mask".

Other bronze artifacts include birds with eagle-like bills, tigers, a large snake, zoomorphic masks, bells, and what appears to be a bronze spoked wheel but is more likely to be decoration from an ancient shield. Apart from bronze, Sanxingdui finds included jade artifacts consistent with earlier neolithic cultures in China, such as cong and zhang.