The primordial qi, also called primary qi or genuine qi, is the most essential qi in the body and the vital foundation of life.

The primordial qi mainly comes from kidney-qi of the parents during pregnancy. That is why TCM usually calls the primordial qi "the congenital qi". The power and quantity of the primordial qi are already fixed after birth. However, after birth the primordial qi still needs further nourishment and enrichment to enable it to be distributed to the whole body and to exert normal physiological effect. The primordial qi transformed from food nutrients provided by the spleen and stomach is called "acquired qi".

The primordial qi is stored in the kidney and distributed to all parts of the body through the triple energizer. The primordial qi transformed from food nutrients provided by the spleen and stomach must be stored in the kidney so that it can be distributed to the whole body. Though the primordial qi is distributed to all parts of the body, it originates from the kidney.

The primordial qi shares the common functions of qi, such as propelling, warming, protecting, fixating and qi-transforming, etc. The functions of the primordial qi are different if its location is different. The characteristics of the primordial qi in the kidney include three aspects, to promote the growth and development of the body and maintain reproductive functions of the body; to promote qi transformation to regulate water metabolism and excretion of urine; to fixate sperm and inhaled fresh air to ensure the functions of the kidney to store essence and receive qi. 

The primordial qi distributed to all parts of the body warms and promotes all the viscera so as to bring their physiological functions into full play. For example, the spleen governs transportation and transformation; the lung governs respiration; the heart dominates blood; the liver controls dredging and dispersing; the stomach is responsible for reception and digestion, etc. These are all the concrete manifestations of the effect of the primordial qi on the viscera. Thus the primordial qi is the vital qi in the body and is the motivation of all life activities. The state of the primordial qi decides the state of life.