The term means that the lung governs and regulates the distribution, transportation, and excretion of water and body fluids through the activities of dispersion, depuration, and descent. That is, the lung regulates water metabolism by means of dispersion, depuration and descent. Through dispersion, body fluids are distributed all over the body and to skin and body hair on body surface to nourish and moisten the whole body. Meanwhile, the lung regulates perspiration through its dispersion of defense qi and control over the opening and closing of striae and interstices. Fluids are distributed downward and inward through the depuration and descent by the lung to nourish and moisten zang-fu organs and tissues. The lung’s regulation of water passage is a manifestation of the dispersion, depuration, and descent governed by the lung in terms of water metabolism.