Caojue baiyun ge 草訣百韻歌 is a song-like text on the calligraphic style of the grass script (caoshu 草書) written during the Northern Song period 北宋 (960-1126) by an unknown person, perhaps Wen Xigu 溫希古.
The original version was apparently altered by a certain Caizhenzi 采真子 (i.e., Tang Hou 湯垕, fl. 1328) during the Huangyou reign-period 皇祐 (1049-1053). The text was included in the popular encyclopaedia Shilin guangji 事林廣記 (Jian'an Chunzhuang Shuyuan 建安椿莊書院 edition). The poem was reprinted several times during the Ming period 明 (1368-1644; Huicheng fang jiu ru 徽城方九如 edition; the officially endorsed edition of 1584; Liankui Studio 連奎館 edition; Han Daoheng 韓道亨 manuscript edition of 1613; Lu Fan 潞藩 print from 1634). A modern facsimile reprint was published in 1976 by the Wenwu Press 文物出版社.
The book introduced into the structure of cursive grass script in the form of a song to facilitate memorisation. The original 120 rhymes with a length of 410 characters were by Caizhenzi transformed into 152 lines, with two lines of 5 syllables each forming one rhyme set, and a total dimension of 760 characters. The edition from 1584 was expanded to a length of 1060 words in 212 lines. Zhu Jinggai 朱敬鑉 (1550-1614) soon opted to cut off the additional verses.
Ma Guoquan 馬國權 edited a modern, annotated version, Yuanke Caojue baiyun ge jianzhu 元刻草訣百韻歌箋注 (Xianggang: Wanli Shudian, 1981).
The poem had a great influence on later generations of calligraphers. In 1705, for instance, Liu Ziliang 劉子良 cut the text into 34 stone steles in the calligraphic version written by the master Dalishan 達禮善.