The Xinxiu bencao (Chinese: 新修本草; pinyin: Xīnxiū běncǎo),^{[lower-alpha 1]} also known as the Tang bencao (Chinese: 唐本草; pinyin: Táng běncǎo),^[1][3] is a Chinese pharmacopoeia written in the Tang dynasty by a team of officials and physicians headed by editor-in-chief Su Jing [zh]. It borrowed heavily from—and expanded upon—an earlier monograph by Tao Hongjing. The text was first published in 659; although it is now considered lost in China, at least one copy exists in Japan, where the text had been transmitted to in 721.

Comprising fifty-three or fifty-four juan (卷) or "chapters",^[4][5] the text ostensibly contained both tujing (圖經) or "illustrated descriptions" and yaotu (藥圖) or "drug pictures",^[6] although these illustrations are no longer extant.^[7] In total, some 850 drugs are listed in the text,^[1] including thirty foreign ingredients that were imported into China via the Silk Road, such as benzoin, oak galls, and peppercorn.^[8]

The idea of a bencao (pharmacopoeia) that would copy and expand on Tao Hongjing's Bencao jing jizhu [zh] was first mooted in 657 by court counsellor Su Jing [zh] (蘇敬),^[2] who went by the alias "Su Gong" (蘇恭) because of an "imperial taboo".^[4] The project was eventually approved by Emperor Gaozong, following which a team of some twenty-two officials and physicians,^[9] including the high-ranking historiographer Xu Jingzong,^[1][10] was assembled to complete the text.^[2]

According to the Tang Huiyao, the Xinxiu bencao was completed "on the 17th day of the first lunar month of the fourth year" of the Xianqing era (656–661).^[6] The text was first published in 659, making it the first state-sponsored pharmacopoeia in China,^[1][11][12] as well as one of the earliest known illustrated pharmaceutical texts.^[2]

The Xinxiu bencao was one of the most comprehensive works of its time.^[5] It was designated by the Tang government as the "official standard with regard to drug usage", although it is unclear how widespread its readership was, given the lack of a printing press then.^[1] By the Song dynasty,^[11] the text had become lost in China, although at least one copy still exists in Japan, where it had been transmitted to in 721,^[3] and fully translated into Japanese as Honzō wamyō in 1918 by palace doctor Fukane no Sukehito.^[9] In the modern era, fragments of the Xinxiu bencao have also been discovered from a book depository in a cave in Dunhuang, Gansu.^[11][13]