The Kan diagram is the sixth diagram of the congenital eight diagrams. Among the acquired eight diagrams, the Kan diagram ranks first. The Kan diagram（☵） is composed of two Yin Yao (up and down) and the Yang Yao (in the middle). The Kan diagram belongs to the Yang diagram.
Kan diagram represents the water of nature, so the symbol of kan diagram looks like the ripple of water, which is the representative of softness outside and hardness inside, but because water is often trapped in low-lying areas, it is also a symbol of danger. In the human body, Kan diagram represents ears, bladder and kidney. In the characters, Kan diagram represents the second boy in family, thief and poor laborer. In the five elements, kan diagram represents water and severe cold. Because China is in the northern hemisphere, kan diagram represents the North geographically; in the season, kan diagram represents winter, and it also represents the year, month, day and hour which the earthly branch is Zi. In terms of color, the diagram represents black.
Kan diagram stands for danger and difficulty, so in Chinese, when encountering difficult things, we say "encountering a kan"; kan diagram also stands for sexual organs, so kan diagram also stands for cheating and love affair.