Since ancient times

people have uses complicated prescriptions for treating serious diseases. Inner Canon of Yellow Emperor 《黄帝内经》puts forward the theory of major prescriptions. ZHANG Zhongjing created Biejiajian Pills（ 鳖甲煎丸）

Shuyu Wan（ 薯蓣丸） and other prescriptions with the method of application of both cold and heat herbs

as well as reinforcement and elimination in combination. He was the forerunner who treat refractory diseases with complicated prescriptions. His thoughts mainly includes treating deficiency by regulating the middle with sweet and relieving herbs

nourishing blood and generating body fluid; treating stasis using insect drugs and bringing forth the new through the old; treating Qi by regulating ascending-descending-exiting-entering and dredging body fluid and blood; as well as treating wind by strengthening body resistance

dispelling wind to clear pathogenic factors and reinforce vital Qi. On methods of taking medicine

ZHANG emphasized that pills took effect slowly and mitigated drug property. Prescriptions corresponding to diseases should be applied and kept using. ZHANG Zhongjing’ s thoughts of composing complicated prescriptions provided feasible guide for clinical differentiation of syndromes and treatment of chronic refractory diseases.