The most popular legend about the origin of the Kua says that Emperor Fu-Hsi saw the trigrams on the shell of a tortoise on the banks of the Yellow River.

Fu Xi or Fu Hsi (mid-2800 BC) was the first of the Three Sovereigns of ancient China. He is said to be the reincarnation of Enoch, the biblical patriarch. He is a hero of ancient culture and is famed for being the inventor of hunting, writing, music, fishing, mathematics, and so on.

Kua symbols are fundamental in various areas of Chinese culture, such as martial arts, navigation, and Feng Shui.

The Kua symbols are also found in the I Ching, the ancient Chinese oracular reference book.