This paper summarized the experience of ZHANG Zhiyuan in clinical application of Huangqin （

Radix Scutellariae

）. It is believed that perennial root of Huangqin mainly drains lung-fire， expelling pathogenic factors from muscles for clearing heat， disperses phlegm and invigorates

qi

， while juvenile root mainly drains large intestine fire， clears heat and dampness， relieves dysentery and removes blood. The perennial root of Huangqin has a hollow shape and can enter the lungs， pass through

sanjiao

（三焦） from the spleen， and reach the bladder， making way for the heat. Therefore， it is especially suitable for high fever caused by external contraction， usually together with

Maxing Shigan Decoction

（麻杏石甘汤） or Chaihu （

Radix Bupleuri

）. It can also be used with Gegen （

Radix Puerariae Lobatae

） to clear

sanjiao

heat and treat dizziness and headache. The juvenile root of Huangqin can reduce fire and eliminate phlegm， dry dampness and relieve diarrhea， cool the blood and stanch bleeding， which is often used in classical formulas

Gegen Qinlian Decoction

（葛根芩连汤） and

Jiangqin Lianshen Decoction

（姜芩连参汤） to treat gastroenteritis related diarrhea and vomiting. In

Huangtu Decoction

（黄土汤），

Huanglian Ejiao Decoction

（黄连阿胶汤） and other classical formulas， large amount of Huangqin is used to stanch bleeding. Self-made

Yuer Decoction

（育儿汤） having juvenile root of Huangqin is prescribed to treat threatened abortion due to blood heat and

yin

deficiency.