Jīng (; Wade-Giles: ching1) is the Chinese word for "essence", specifically kidney essence, or semen. Along with Qi and Shen, it is considered one of the Three Treasures San Bao 三寶 of Traditional Chinese Medicine or TCM. In TCM, jīng is stored in the kidneys and is the most dense physical matter within the body (as opposed to shen which is the most volatile).