Systemic sclerosis（ SSc） of early stage mostly belongs to "skin Bi"（ 皮痹） in Chinese medicine category. In the later stage

"lung Bi"（ 肺痹）

"lung flaccidity"and other diseases complicates. It is said in Bi Discussion（ 痹论） in Plain Questions（ 素问） that "disorder of nutrient Qi and defensive Qi"is an important internal cause leading to Bi syndrome. The authors try to discuss from the aspects of physiological and pathological characteristics of nutrient Qi and defensive Qi

Chinese medical pathogenesis of SSc complicated with pulmonary interstitial changes in different stages

as well as the meaning of harmonizing nutrient Qi and defensive Qi and other methods in treating SSc complicated with pulmonary interstitial changes

to provide prompt for clinical therapy.