The Mysterious Woman of the Ninth Heaven (Jiu Tian Xuan Nu 九天玄女) is a powerful Taoist deity, who taught the Yellow Emperor and gave him esoteric texts on military arts that helped him win a cosmic battle. She also gave him texts on alchemy and immortality.She is also known as the Feng Shui Goddess who brought knowledge of feng shui to the Yellow Emperor. She is an important figure in feng shui theory and practitioners today frequently employ statues of the Mysterious Woman of the Ninth Heaven.This immortal is sometimes called the Goddess of the Nine Heavens – in Taoism there are nine layers of heaven and layers of the underworld. Xuan Nv was one of Xi Wang Mu's disciple (西王母之徒) that assist Xi Wang Mu in delivery important messages to humankind. Xuan Nv was also thought to be a disciple of Tai Yuan Sheng Mu 太元聖母 (which is a very old ancient Female Deity.)

The goddess – who probably originated as a bird-like deity – is not as elevated as the Jade Emperor or Very High Lord (Tai Shang Lao Jun 太上老君), but she appears in many legends and classical novels as a goddess of justice who helps heroes in danger. She is the benevolent goddess who has protected people and delivered babies since the Song Dynasty (960-1279). She is associated with the arts of warfare, martial arts, shamanism, alchemy, feng shui, sexual alchemy (Taoist sexual practices for longevity) and divination. Foretelling the future by observing changes in nature was very popular from the Han Dynasty (206 BC-AD 220) to the Jin Dynasty (AD 265-420).

The earliest depictions of the Mysterious Woman show a deity with a woman’s head and a bird’s body, perhaps indicating relationship with early worship of bird totems. Taoists depict her as a rosy-face woman usually brandishing a sword in her right hand. In he left hand she holds a Taoist double gourd, a symbol of immortality, healing and longevity. She rides a phoenix, using clouds as reins and wears garments made of nine colors of bird feathers.The Mysterious Woman is famous for assisting the Yellow Emperor, legendary ancestor of the Chinese people, to defeat the monster Chi You in a cosmic battle. Chi You created a three-day fog that darkened the sky and blinded soldiers, and the emperor was defeated in nine engagements.

The Yellow Emperor was not the only ruler who received help from the goddess. Liu Bang, the first emperor of the Han Dynasty, was also the beneficiary of her power. Since the capital and palace of the Qin Dynasty (221-206 BC) were destroyed by the fire set by Xiang Yu, the king of Chu, Liu had to relocate the capital. He chose Bailuyuan in today’s Shaanxi Province, but a terrible earthquake turned the land into sea. The Mysterious Woman of Nine Heavens appeared and restored the original land by spreading a handful of earth. She told the emperor a giant whale was lying under the land. He then chose Chang’an for a capital, but a dragon beneath the land caused the ground to crack and rumble. The goddess again appeared and subdued the dragon so the new capital could be built. During the Spring and Autumn Period (776-467 BC), the Mysterious Woman of Nine Heavens also helped the Yue State by training an invincible army of 6,000 soldiers who defeated the Wu State.

The Mysterious Woman wearing colorful feathers arrived on a phoenix and declared herself to be the Goddess of Nine Heavens. She gave the emperor a talisman, a magical sword, seal, Chinese compass and other instruments, as well as texts on warfare. Thus armed, the emperor was victorious, united the Chinese people and became immortal. The legendary books and documents from the goddess were passed down through history. They were said to contain secrets of longevity and achieving immortality through alchemy and Taoist sexual practices.