"Feminine Alchemy "( 女丹 Nüdan ) is a term of Inner Alchemy ( 內丹 Neidan ). This expression has two senses. It both refers to the Inner Alchemy practiced by females, and the methods of this practice. Ever since its beginnings, Daoism has pursued the principle of having an impartial attitude towards heavenly and terrestrial governing, and has held the opinion that females can also cultivate the Dao and attain immortality. Consequently, female immortals constitute a large part of Daoist hagiography. When Daoist Inner Alchemy arose, many females practiced Inner Alchemy cultivation as well and formed cultivation methods fit for females. The method of "Feminine Alchemy" cultivation is also called "feminine method", "the way of Refining the Form through Supreme Yin " ( 太陰煉形 Taiyin Lianxing ), etc. It is an advanced way of cultivation. Primordial Sovereign ( 元君 Yuanjun ) Sun Bu’er, one of the Seven Perfect Ones of the North ( 北七真 Bei Qizhen ) of the Complete Perfection tradition ( 全真 Quanzhen ), wrote a book Instructions for Feminine Alchemy ( 坤訣 Kunjue ), which says the methods of "Feminine Alchemy" are the "steps leading to heaven" and the "boat that benefits mankind". It fully proves that Feminine Alchemy was regarded as important by female Daoists. Female alchemical cultivation has become a phenomenon not to be ignored since the Ming and Qing dynasties. The Selections from the Daoist Canon ( 道藏輯要 Daozang Jiyao ) collects a small series called Collected Essays on Feminine Alchemy ( 女丹合編 Nüdan Hebian ), which includes dozens of texts, such as the Book of Feminine Origin ( 坤元經 Kunyuan Jing ), Ten Feminine Alchemical Instructions of the Spiritual Fruit of the Kettle Heaven ( 壺天性果女丹十則 Hutian Xingguo Nüdan Shize )), Feminine Golden Elixir ( 女金丹 Nü Jindan, etc. They are important sources for the study of Feminine Alchemy. Though having something in common with masculine alchemical cultivation, feminine alchemical cultivation still has its own characteristics. Does Inner Alchemy have its practical value in the present age? This subject needs reexamination.