Shuanggudui (simplified Chinese: 双古堆; traditional Chinese: 雙古堆; pinyin: Shuānggǔduī) is an archeological site located near Fuyang in China's Anhui province. Shuanggudui grave no. 1, which belongs to Xiahou Zao (夏侯灶), the second marquis of Ruyin (汝陰侯), was sealed in 165 BCE in the early Han dynasty (206 BCE – 220 CE). Excavated in 1977, it was found to contain a large number of texts written on bamboo strips, including fragments of the Classic of Poetry and the Songs of the South, a text on breathing exercises, a "year table" (年表) recounting historical events, a manual on dogs, a version of the I Ching (Yijing) that differs from the received one, and artifacts including the oldest known cosmic board, a divinatory instrument. Like Mawangdui and Guodian, two other tombs from the area of the old state of Chu, the Shuanggudui find has shed great light on the culture and practices of the early Han dynasty.

Shuanggudui (双古堆; 'paired ancient tumuli') was excavated in July 1977 during the expansion of the Fuyang municipal airport in Anhui province, China. Located about two miles outside Fuyang at the time, the site was known to contain old tombs, yet it is unclear whether the excavation was pre-planned or rushed just as construction started. The digging was supervised by two archeologists from the Anhui Provincial Archaeological Relics Find Team, who discovered two tombs, one of which (Tomb 1, to the east) was found to contain texts and artifacts. A ramp 4.1 metres (13 ft) wide led to a coffin chamber measuring 9.2 metres (30 ft) north-south by 7.65 metres (25.1 ft) east-west, about half the area of the more famous Tomb 3 that had been discovered in Mawangdui in 1973.

Some of the bronze artifacts found in Tomb 1 were marked with the name of the tomb's occupant Ruyin Hou (女［汝］陰侯), which means "Lord of Ruyin". This title had first been granted to Xiahou Ying (d. 172 BCE), who had helped Liu Bang (r. 202–195 BCE) to establish the Han dynasty. Archeologists have identified the tomb as belonging to Ying's son Xiahou Zao, the second Lord of Ruyin. Little is known about him, except that he died seven years after his father. The tomb is therefore thought to have been sealed in 165 BCE, the fifteenth year of Emperor Wen's reign.

The Shuanggudui tomb contained the earliest known diviner's boards (式; shi), or "cosmographs", divinatory instruments that were widely used during the Han dynasty (206 BCE – 220 AD). These two lacquered astrological boards consist of a movable disk – 9.5 centimetres (3.7 in) in diameter – representing the Heavens mounted on a square base – 13.5 by 13.5 centimetres (5.3 by 5.3 in) – representing Earth. The center of the circular top depicts the seven stars of the Northern Dipper (which was considered to be a powerful astral deity), whereas the rim of both the disk and the square base is inscribed with astro-calendrical signs that helped to perform divination. Donald Harper, who wrote about this artifact soon after its discovery, argued that it should be called a "cosmic board" because it is "so obviously a mechanistic model of the cosmos itself".

The use of such boards is described or alluded to in many ancient Chinese texts like the Chu Ci, Han Feizi, Huainanzi, and some military texts. The diviner would rotate the disk until the Dipper pointed in a chosen direction, usually corresponding to the current date. He would then find an answer to his question by means of numerological calculations. Manipulation of this miniature model of the cosmos was supposed to bring power to its user.

Numeral juxtaposition on the inner, round part of the board correlates to the Luoshu layout, which was long supposed to have been invented in the Six Dynasties (220–589). This is the most ancient occurrence of the Luoshu magic square. "The inscriptions ... appear to belong to ... the 'Circulation of Taiyi among the Nine Palaces.'" (太一行九宮; Taiyi xing jiugong)

The most valuable goods that were buried with Xiahou Zao had long been robbed when archeologists excavated the tomb in 1977. In addition to the two cosmic boards, many lacquered vessels were found, as well as terra cotta musical instruments, metallic weapons (a few made of iron but most of bronze), and a number of bronze artifacts like a mirror, a lamp, and a cauldron.

Robbers who looted the tomb in the late second century CE took the bamboo strips out of the lacquered bamboo hamper in which they had been placed and left the strips on the ground of the coffin chamber. The chamber itself later collapsed, breaking the strips, and muddy water covered the strips, eventually turning them into "paper-thin sheets, fused together into clumps by ground pressure." The largest of the three clumps was about 25 centimetres (9.8 in) long by 10 centimetres (3.9 in) wide and 10 centimetres (3.9 in) high. To complicate matters, the 1977 excavation took place under a heavy rainstorm, and the pump that the excavators used to remove mud from the coffin chamber also pumped out other fragments of bamboo strips.