Rehmannia glutinosa, Cornus officinalis and Dioscorea opposita are the three tonic drugs, and Liuwei Dihuang Pill is the monarch drug. Dihuang is used to nourish yin and tonify kidney, and replenish essence and marrow. Cornus officinalis nourishes liver and kidney and can astringent essence, indicating that liver and kidney are homologous. Yam can tonify spleen and yin, and also tonify kidney. * * * is the Minister of Medicine. The three herbs, kidney, liver, spleen and three yin, are three tonics, but the dosage of Radix Rehmanniae Preparata is the sum of Cornus officinalis and Dioscorea opposita, so it is mainly to tonify the kidney. Alisma orientalis can reduce the nourishing and greasy of Radix Rehmanniae Preparata, while Poria cocos can slightly permeate spleen dampness, which is helpful for the healthy transportation and transformation of yam. Together with Alisma orientalis, it can expel kidney turbidity, help true yin return, clear deficiency and heat, and control the warmth and astringency of Cornus officinalis. The three drugs are called three diarrhea, and they are all auxiliary drugs. The combination of six flavors, three tonics and three diarrhea, in which the dosage of tonics is heavier than that of laxatives, and the liver, spleen and kidney are supplemented by three yin, which is the compatibility feature of this prescription.