Abstract： Objective： To observe the clinical effect of the therapy of modified Mufangji tang and Chinese herbs iontophoresis on diffuse pulmonary interstitial fibrosis of qi deficiency and phlegm-stasis type. Methods：A total of 60 patients with diffuse pulmonary interstitial fibrosis were randomly divided into the observation group and the control group，with 30 cases in each group. The control group was orally given prednisone tablets based on the antibacterial and symptomatic supportive treatment，and the observation group was additionally given the therapy of modified Mufangji tang and Chinese herbs iontophoresis based on the treatment of the control group. Both groups were treated for four weeks. The clinical effects in the two groups after treatment， and the Chinese medicine syndrome scores， levels of lung function indexes including forced vital capacity(FVC)， the percentage of FEV1 to evaluated value(FEV1% )， diffusing capacity of the lungs for carbon monoxide(DLCO) and oxygen partial pressure(PO2)，whole blood leukocytes，neutrophils，eosinophils，vascular endothelial growth factor(VEGF)，tumor necrosis factor-α(TNF-α)，interleukin-1 β(IL-1β) and interleukin-6(IL-6) in alveolar lavage fluid before and after treatment were observed. Results：After treatment，the total effective rate was 90.00% in the observation group and 56.67% in the control group，the difference being significant(P＜0.05). Before treatment，there was no significant difference in Chinese medicine syndrome scores between the two groups(P＞0.05). After treatment，the Chinese medicine syndrome scores in both groups were significantly lower than those before treatment(P＜0.05)， and the score in the observation group was significantly lower than that in the control group(P＜0.05). Before treatment，there was no significant difference in the levels of FVC， FEV1% ， DLCO and PO2 between the two groups(P＞0.05). After treatment， the improvement of the above lung function indexes in both groups was better than that before treatment(P＜0.05)， and the improvement of the above indexes in the observation group was more significant than that in the control group(P＜0.05). During treatment， the levels of whole blood leukocytes， neutrophils and eosinophils in both groups before and after treatment showed no significant significance(P＞0.05). Before treatment，there was no significant difference in the level of serum VEGF between the two groups(P＞0.05). After treatment， the level of serum VEGF in the observation group was decreased when compared with that before treatment(P＜0.05)，and the above level in the observation group was lower than that in the control group(P＜0.05)； the VEGF level in the control group was not significantly different from that before treatment(P＞0.05). Before treatment，there was no significant difference in the levels of TNF-α，IL-1β and IL-6 in alveolar lavage fluid between the two groups(P＞0.05). After treatment，the above three levels in both groups were decreased when compared with that before treatment(P＜0.05)，and the above three levels in the observation group were lower than those in the control group(P＜0.05). Conclusion：On the basis of conventional treatment，the therapy of modified Mufangji tang and Chinese herbs iontophoresis has a significant effect on diffuse pulmonary interstitial fibrosis of qi deficiency and phlegmstasis type， which can improve the Chinese medicine syndrome and the VEGF level， reduce inflammatory responses and improve lung function.