This paper summarized ZHANG Zhiyuan's clinical experience of using Dihuang （

Radix Rehmanniae

）. It is believed that Dihuang is good at supplementing essence and marrow， nourishing the liver and kidney， and is commonly used for stroke sequelae，

yin fei

（瘖痱： tongue stiffness failing to speak and the four limbs failing to move）， and brain ringing. Shengdihuang （

Rehmannia Glutinosa

） is good at enriching

yin

and moistening dryness， unblocking blood and vessels， relax the sinews and quicken the collaterals， which can be used to treat Lily disease，

xiaoke

（消渴）， wind-damp

bi

（痹） and spleen-stomach diseases， and large dose helps moisten the intestines to promote defecation and treat intractable constipation. It should also be noted that Shengdihuang cannot be used frequently in patients with spleen deficiency and damp stagnation. abdominal fullness and thin， unformed stool as of its cold nature. The herb Sharen （

Fructus Amomi

） should be added when using Shudihuang （

Radix Rehmanniae Praeparata

） in large dose to prevent the

qi

movement blockage in middle

jiao

（焦）， as it is sticky， greasy， and brings damage to digestion.