Zhoushu 周書 "Book of the (Northern) Zhou" is the official dynastic history (zhengshi 正史) of the Northern Zhou dynasty 北周 (557-581), one of the Northern Dynasties 北朝 (386~581). It was written by Linghu Defen 令狐德芬 (583–666) and comprises 50 juan, 8 of which are imperial annals-biographies (benji 本紀), and the rest normal and collective biographies (liezhuan 列傳). Treatises on the Northern Zhou empire can be found in a compound collection of treatises in the history Suishu 隋書.
During the Song period 宋 (960-1279) a great part of the book was already lost. In the modern version juan 18, 24, 26, 31 and 32 are missing. Juan 31 and 32 have been supplemented from the parallel dynastic history Beishi 北史, juan 24 and 26 from Gao Jun's 高峻 history Gaoshi xiaoshi 高氏小史 (lost). In some bibliographies the book is called Houzhoushu 後周書 "Book of the Later Zhou", which makes matters somewhat complicate because the last of the Five Dynasties 五代 (907-960) was also called the Later Zhou (951-960). The Zhoushu must also not be confounded with the chapter of the same title that is part of the Confucian Classic Shangshu 尚書.
Linghu Defen was an important historian during the early Tang period 唐 (618-907). He suggested to the emperor compiling a history of the short-lived Zhou Dynasty, as well as of the Northern Qi 北齊 (550-577) and the Southern dynasties 南朝 (420-589) Liang 梁 (502-557) and Chen 陳 (557-589), as long as there was still source material available. A very important point was that the ancestors of the Tang dynasty had acted as officials of the Zhou dynasty, so that the Northern Zhou could be seen as the direct predecessor of the Sui and Tang dynasties.
In 929 Linghu Defen, Cen Wenben 岑文本 and Cui Renshi 崔仁師 took over the compilation of the Zhoushu. It was completed in 636.
The collective biographies include those for imperial consorts (9 Huanghou liezhuan 皇后列傳), princes (10-13), Confucian scholars (45 Rulin liezhuan 儒林列傳), persons of filial conduct (46 Xiaoyi liezhuan 孝義列傳), magicians and diviners (47 Yishu liezhuan 藝術列傳) and "barbarians" (49-50 Yiyu liezhuan 異域列傳).
Chapter 48 includes the biographies of Xiao Yu 蕭詧, called Emperor Xuan 梁宣帝 (r. 555-561), founder of the Later Liang dynasty 後梁 (555–587), and his family and courtiers.
Although the content of the Zhoushu is quite reliable, the authors laid too much stress on an elaborate literary style. Primary sources are thus not preserved in the original version.
The bibliographic chapter Jingji zhi 經籍志 in the dynastic history Suishu 隋書 lists an unfinished book called Zhoushi 周史 (18-juan long), written by Niu Hong 牛弘 (545–610, courtesy name Liren 里仁). The same title is known from a 10-juan long book written by Wu Jing 吳兢.