The incidence of diffuse pulmonary interstitial disease（DPID） is rising year by year at present.The article discussed emphatically the occurrence and development of DPID at the level of TCM pathogenesis

and found out that disorder of qi activity runs throughout DPID.The disorder of qi activity refers to qi deficiency

qi insufficiency or abnormal activity of qi induced by weak engendering transformation of qi or overconsumption of qi

and its pathological products such as phlegm

deficiency and stasis are the dominant factors in the development of DPID.The authors discussed the influence of disorder of qi activity on DPID from the aspects of the independent factors（phlegm

deficiency and stasis）

and offered the theory basis for syndrome differentiation and treatment of DPID.