Idiopathic pulmonary fibrosis（ IPF） closely relates to deficient dyspnea in Chinese medicine. The causes and pathogenesis of both diseases matched each other. IPF could be treated as deficient dyspnea. The authors hold that Qi deficiency is the primary cause of deficient dyspnea

and deficiency of kidney essence is the key pathogenesis. Deficiency of Qi and kidney essence exists throughout the process of disease development. Therefore treatment of IPF should be mainly invigorating Qi and benefiting kidney which is the main therapy of deficient dyspnea.Zhenyuan Yin（ 贞元饮） is an important prescription of ZHANG Jingyue to treat deficient dyspnea. The main effect is invigorating kidney and benefiting essence. Adding Renshen [Radix Ginseng

人 参] and Huangqi [Astragalus membranaceus

黄芪] could invigorate Qi and benefit kidney

which is effective in treating IPF.