In ancient China, the number nine was regarded as the extreme of positive numbers, i.e. the maximum of singular. For this reason, it was associated with emperors and matters connected with emperors. The imperial throne was named nine and five. An emperor was called honor of nine and five. Other matters concerning the number nine are listed below:

There was a kind of bronze cooking vessel with nine legs, and emperors established a system of nine ministers.

Of the ancient feudal government officials, there was one called nine-level; there were nine capital armies in the capital city.

There were nine thousand nine hundred and ninety and a half houses in the Forbidden City.

Gate tower of the Tian'an Men has nine bays in width and in length.

Gates of Chinese Forbidden City, imperial gardens and Xanadus were decorated with nine road nail, which meant there were nine doornails both vertically and horizontally in one door, altogether 81 nails.

In the Qing Dynasty (1644-1911), the maharajas of different tribes were required to submit to the emperor eight white horses and one white camel annually, which were named nine white tributes. Most often, other articles of tribute were calculated with reference of the number nine. For instance, in the 13^th year during the reign of Emperor Kangxi, he stipulated that Banners like Ke'erqin Banner should submit to the royalty the following articles of tribute in the quantity of twelve times nine: 108 goats, 108 bottles of koumiss annually; Banners like Erdos should submit 81 goats and 81 bottles of koumiss annually.

During the construction of temples in ancient China weight of golden Buddha was also calculated in nine, usually 81 jin (half kilogram) or 72 jin, and quantity of figures of Buddha was calculated in nine. For example, in the 45^th year during the reign of Emperor Kangxi, 2,299 times 9 figures of Buddha were built (altogether 20,691) to celebrate his 70th birthday.

The feasts of annual festivals of royal court of the Qing Dynasty (1644-1911) consisted of 99 kinds of foods including fruit, succade and snacks.

Upon emperors' birthday in the Qing Dynasty, entertainment activities including acrobatics performance, lighting up eternity spring lamps, and so on, would be performed. There should be 9*9 (81) kinds of such entertaining activities, named nine nine big celebration. Foods, entertaining programs and tributes from governmental officials for emperors' birthday and Chinese Spring Festival in the Qing Dynasty were also numbered in nine, meaning to wish the emperor long life. Gradually, the number nine was exclusively used by the emperor; as a result, the ordinary people including high-ranking officials and royal family members were prohibited from using the number nine in their daily life.