Zouzi 鄒子 "Master Zou" is a book the school of Yin-Yang thinkers (yinyangjia 陰陽家). Its origins are unknown because it not listed in the early imperial bibliographies in the official dynastic histories Suishu 隋書 and Xintangshu 新唐書. Ma Zong's 馬總 (d. 823) encyclopaedical collection Yilin 意林 from the Tang period 唐 (618-907), and the Song-period 宋 (960-1279) encyclopaedia Taiping yulan 太平御覽 are the first bibliographies that mention the book Zouzi.
The questions of the author and the date of compilation are far from being solved. Although the Han-period 漢 (206 BCE-220 CE) bibliography Yiwen zhi 藝文志 mentions the books Zouzi and Zouzi zhongshi 鄒子終始 as writings of the school of Yin-Yang thought, it cannot be ascertained that these are identical to the surviving fragments of the book Zouzi. Ban Gu 班固 (32-92 CE) remarks in his Yiwenzhi that the Zouzi had a length of 49 chapters and was written by Zou Yan 鄒衍, who hailed from the state of Qi 齊, was an instructor of King Zhao 燕昭王 (r. 311-279) of the state of Yan 燕 and later an erudite at the Jixia Academy 稷下.
In the the biographic chapter on Meng Ke 孟軻 (Mengzi 孟子, 385-304 or 372-289 BCE) and Xun Kuang 荀況 (Xunzi 荀子, 313-238 BCE) in the history Shiji 史記 it is said that Zou Yan had written the books Zhongshi 終始 "End and Beginning" and Dasheng 大聖 "The Great Holy". The same chapter, and the book Lüshi chunqiu 呂氏春秋 provide some information on the philosophy of Zou Yan, but of his writings only a few fragments have survived.
Although Han period scholars classified Zou Yan as a theoretician of Yin-Yang thought, he is in the above-mentioned sources seen as a philosopher of the Five Agents (wuxing 五行, wude 五德) theory who connected the cyclical and spontaneous change of the Five Elements with regions of China. This can also be seen in the fragments of his books, where the "beginning and end" of the Five-Agents cycle is explained and the agents' relation to the "great nine provinces" (da jiuzhou 大九州).
The Qing period 清 (1644-1911) scholar Ma Guohan 馬國翰 (1794-1857) published the surviving fragments of the Zouzi in his series Yuhanshanfang yiji shu 玉函山房輯佚書. Fragments can be found in the books Lüshi chunqiu, Huainanzi 淮南子 and the history Shiji. A further collection of fragments was compiled by Wang Renjun 王仁俊 (1866-1913), called Zouzi shu 鄒子書, which is to be found in the Yuhanshanfang jiyi shu xubian 玉函山房輯佚書續編.
There is another book called Zouzi, written by a Jin-period 晉 (265-420) scholar called Zou Zhan 鄒湛, courtesy name Runfu 潤甫, from Nanyang 南陽. He occupied the state offices of cavalier attendant-in-ordinary (sanji changshi 散騎常侍), chancellor of the National University (guozi jijiu 國子祭酒) and was later chamberlain for the palace revenues (shaofu 少府) and died during the 290s. He had written 25 poems and treatises. The books listed in the Yilin are arranged in chronological order, and the Zouzi appears just among Western-Jin-period 西晉 (265-316) writings like Cai Hong's 蔡洪 Huaqingjing 化清經 or Sun Min's 孫毓 Chengbaizhi 成敗志. It can therefore be concluded that the Zouzi fragments of the Yilin are from Zou Zhen's book, and not from the writings of the ancient master Zhou Yan. There exists, nonetheless, the problem that no such book of Zou Zhen is mentioned in his biography in the history Jinshu 晉書, nor in the imperial bibliography Jingji zhi 經籍志 in the history Suishu 隋書.
Fragments from Zou Zhen's book are included in Ma Guohan's collection, too, but under the section "miscellaneous writings" (zajia lei 雜家類).