Zhou Yi (Changes of Zhou), also called Yi or Yi Jing, is one of the important classics of Confucianism, including two parts: scripture and commentary, and 64 divinatory symbols. It contains mainly the thoughts of Confucianism, but also covers the thoughts of Taoism and the Yin-Yang School.

Yi has three meanings, i.e. Bian Yi (change), Bu Yi (no change) and Jian Yi (simple). Bian Yi (change) means that moving and changing is the law in the world; Bu Yi (no change) means relative stability; Jian Yi (simple) means to control the millions with one, control the complex with the simple. Zhou Yi predicts the social affairs with Yin and Yang (opposite principles or forces existing in nature and human affair). Thus, it contains rich dialectic thoughts. Besides philosophy, Yi also involves the astronomy, geography, music, military, making pills of immortality with ovens, medicine, augury, astrology, etc, even the theory of modern science originates from Yi, e.g. the binary digit for computer.