Sunü (Chinese: 素女; pinyin: Sùnǚ) is a figure in Chinese mythology associated with music and sexual cultivation. She appears in early Chinese texts, including the Shiji (Records of the Grand Historian) and the Classic of Mountains and Seas (Shan Hai Jing). Later texts associate her with fangzhong shu (sexual cultivation) and Xuannü.
The Shiji records a story about Sunü and the se, a Chinese zither. In the account, Tai Di (太帝) ordered Sunü to play a fifty-stringed se. The music was sorrowful, and Tai Di broke the instrument into two, producing a twenty-five-stringed se.
The Classic of Mountains and Seas states that Sunü came from Duguang (都广).
Sunü is also associated with fangzhong shu, a tradition of sexual cultivation in ancient China. The Sunu Jing (Classic of Sunü) is one of the texts associated with this tradition. The original text has been lost, but material attributed to it was preserved in Tamba no Yasuyori's Ishinpō, compiled in Japan in 984.
Zhang Heng's Eastern Han poem Tongsheng ge (同声歌) mentions Sunü in a passage about a newly married couple. The speaker says, "Sunü is my teacher" and describes her as having yitai ying wanfang (仪态盈万方), praising her graceful appearance.
The Sunu Jing is presented as a dialogue between the Yellow Emperor and Sunü and discusses sexual practices and the preservation of health. Sunü and Xuannü are associated with the arts of the bedchamber, and the expression xuansu zhidao (玄素之道), or the "Way of Xuan and Su", was used in connection with these practices.
A different tradition concerns Bai Shui Sunü (白水素女, "White Water Sunü"). In Soushen Houji (Supplement to In Search of the Supernatural), Xie Duan of Houguan finds a large snail shell. A young woman emerges from it and tells him that she is Bai Shui Sunü from the Milky Way. She says that the Heavenly Emperor sent her to help him because he was an orphan who lived carefully and virtuously. She prepares food for him and helps him become prosperous. After Xie Duan discovers her identity, she leaves in a storm, leaving the shell behind so that he can store grain in it. Xie Duan later establishes a shrine for Bai Shui Sunü and makes seasonal offerings to her. The story ends by stating that a shrine to Sunü existed along the road.