By reviewing the theory of the unyielding and the soft and analyzing the connotations of the three-her combination， this article has selected five representative three-herb combinations from

Treatise on Febrile Disease

（《伤寒论》） and deeply explored the combination rules of the medicinals with coordination between the unyielding and the soft. Xixin （

Radix et Rhizoma Asari

）， Ganjiang （

Rhizoma Zingiberis

） and Wuweizi （

Fructus Schisandrae Chinensis

） can open and close the lung

qi

， using the soft to balance the unyielding. The combination of Maziren （

Fructus Cannabis

）， Shaoyao （

Radix Paeoniae Alba seu Rubra

） and Dahuang （

Radix et Rhizoma Rhei

） embodies the principle of balancing the unyielding and the soft， enriching the spleen while draining the stomach. Fuzi （

Radix Aconiti Lateralis Praeparata

）， Fuling （

Poria

） and Shaoyao can warm the kidneys and soften the liver， rectify the healthy

qi

and promote urination. Huanglian （

Rhizoma Coptidis

）， Ejiao （

Colla Corii Asini

） and Jizihuang （

Ovum Gallus

） can clear the heart， enrich the kidneys， and restore the interaction between water and fire. Wumei （

Fructus Mume

）， Huanglian and Chuanjiao （

Zanthoxylum bungeanum

） control the unyielding with the soft， harmonizing and regulating

jueyin

（厥阴）. Through analyzing three-herb combinations， it is explained that the coordination between the unyielding and the soft is one of the key principles in the combination of medicinals of classical formulas， which offers insights into the interpretation of classic formulas and the clinical application of the theory of thre

e-herb combination.