Li Xun, styled Derun, was born in Zizhou, Sichuan (now Santai, Sichuan). He lived approximately from the late 9th century to the early 10th century, with exact birth and death dates unknown. He was a literary figure and materia medica scholar during the late Tang and Five Dynasties periods. Li Xun's ancestors originated from Persia and came to China during the Sui Dynasty. In the early Tang Dynasty, they adopted the imperial surname Li. During the An Lushan Rebellion, the family settled in Zizhou, Sichuan, and became known as native Persians of Shu. Li Xun had two known siblings: his elder brother Xun and his younger brother Xuan, styled Yanyi, also known as Li Silang, who enjoyed traveling, cultivating life, and particularly took pleasure in refining vermilion pills, sparing no expense. He made a living selling aromatic medicines and once served as an official under Wang Yan's crown prince.

Li Xun was well-versed in literature, skilled in composing lyrics, and renowned for his poetry. He was a prominent literary figure of the "Flower and Moon School" during the Five Dynasties period. The Ten Kingdoms Chronicles records that Li Xun authored the Qiongyao Collection in several volumes (now lost). In his later years, he lived in seclusion, devoted to life cultivation and alchemy. He traveled to regions such as Jiangsu, Zhejiang, and Guangdong.

Li Xun had considerable expertise in pharmacology. He traveled extensively in Lingnan (southern China), immersing himself in the southern landscapes and familiarizing himself with many medicines introduced from overseas. He authored the Hai Yao Materia Medica in six volumes, notable for its citations of maritime medicinal literature. Based on surviving fragments, the work documented 124 medicinal substances, 96 of which were marked with foreign origins. For example, benzoin and Terminalia chebula came from Persia, borneol camphor from Luyin, and gold flakes from the Arab world. The book also detailed the morphology, authenticity, quality, properties, therapeutic uses, prescriptions, administration methods, preparation techniques, contraindications, and incompatibilities of the medicines. Some entries included explanations of drug names. It recorded substances such as Coral-Bean Bark, Cinnamomum pedunculatum, and myrrh, which were absent in other contemporary materia medica works. Unfortunately, the original text was lost by the Southern Song Dynasty, and its contents are now scattered in works such as the Zheng Lei Materia Medica and Bencao Gangmu.