[Chinese 亩; 畝]

For the Iranian unit, see mu. For the Burmese unit, see mu.


In China, an ancient unit of land area; since 1959, two units, both metrified forms of an earlier unit. See history. Also romanized as mou.

In the market system (shì zhì link to a table showing relationships between Chinese units of land area in the shì zhì system), the shìmǔ 市亩, as applied to agricultural land, = 666 ²⁄₃ square meters (UN, 1966). This = 60 square zhang, about 0.165 acre.

In the gon zhì system link to a table showing relationships between Chinese units of land area in the gon zhì system, a metrified version of the shì zhì system, another unit, the gongmu, also applied only to agricultural land, = 100 square meters.

The mu does not appear in the standard metric system (gong zhì) or in the shì zhì system as applied in general, whose units of area are all squares with sides equal to the shì zhì units of length.


In Taiwan, a unit of land area = 30 p'ing, about 99.174 square meters (about 0.02451 acre). This value is about 0.14876 shì zhì mu.


In the early Zhou the mu = 100 square bu. (The 100-bu mu was sometimes called a xiaomu or Zhou mu.) Around 350 bce, a mu of 240 bu was introduced (sometimes called a damu). Conceptually, it was a strip of land one bu wide and 240 bu long, or a plot 15 × 16 bu. After a period of coexistence, in 104 bce the 240-bu mu became the general standard, and thereafter varied as the number of chi in a bu and the length of the chi changed.

In the Tang Dynasty every adult male was entitled to the loan of 80 mu of land, to be returned to the state on his death, and 20 mu of personal, inheritable land. Seniors and invalids got 40 mu, widows 30, monks 20, and craftsmen and merchants 10.

There was a great deal of regional and local variation.

Period Size of mu,
square meters
Early Zhou 192
Han to Tang 457-523
Song 573
Yuan 840
Ming 640
Qing 706
Shanghai, by order of
the Municipal Council
6,600 square feet
customs treaty 920.417 square yards
769.59 square meters
based on a chi of 14.1 inches

Ochi Shigeaki.
Ichiho hihyakuyonjû-ho sei o megutte. (On the 240-bu mu system).
Tōhōgakuhō, vol. 53, pages 21–35 (1977).

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